Vehicle lighting fixture

ABSTRACT

A vehicle lighting fixture is configured to form a predetermined light distribution pattern (for example, a high-beam (driving) light distribution pattern and a low-beam (passing) light distribution pattern) by superimposing N partial light distribution patterns wherein N is a natural number of 2 or more. The vehicle lighting fixture can include a light intensity changing unit configured to change a light intensity of at least one partial light distribution pattern out of the N partial light distribution patterns.

This application claims the priority benefit under 35 U.S.C. § 119 ofJapanese Patent Application No. 2014-147501 filed on Jul. 18, 2014,which is hereby incorporated in its entirety by reference.

TECHNICAL FIELD

The presently disclosed subject matter relates to vehicle lightingfixtures, and in particular, to a vehicle lighting fixture that uses aplurality of laser light sources.

BACKGROUND ART

Vehicle lighting fixtures that use a plurality of laser light sourceshave conventionally been proposed, as illustrated in, for example,Japanese Patent Application Laid-Open No. 2013-016277 (orUS2014/0168940A1 corresponding to the Japanese publication).

FIG. 1 is a schematic diagram illustrating the configuration of avehicle lighting fixture 301 described in Japanese Patent ApplicationLaid-Open No. 2013-016277.

As illustrated in FIG. 1, the vehicle lighting fixture 301 can include aplurality of laser light sources 302, a plurality of condenser lenses311 and a plurality of optical fibers 312 provided corresponding to theplurality of laser light sources 302, a lens 313, a reflective mirror314, a light emitting unit 304 (or a wavelength conversion member), areflector 305, etc. Rays of laser light emitted from the plurality oflaser light sources 302 can be collected by the respective condenserlenses 311 and incident on the respective input ends (input end faces)of the respective optical fibers 312. The rays of laser light guidedthrough the respective optical fibers 312 can then exit throughrespective output ends (output end faces) of the respective opticalfibers 312, and can be collected by the lens 313 and reflected by thereflective mirror 314. The reflected rays of laser light can be incidenton the light emitting unit 304 to serve as excitation light. Thus, theexcited wavelength conversion material contained in the light emittingunit 304 can emit light, so that the original rays of laser light andthe light from the wavelength conversion material can be mixed. As aresult, the light emitting unit 304 can serve as a light source.

Therefore, the vehicle lighting fixture 301 with the above-describedconfiguration can simply project light from the light emitting unit 304(wavelength conversion member) forward by means of the reflector 305.Accordingly, the vehicle lighting fixture 301 cannot form predeterminedlight distribution patterns formed by superimposing a plurality ofpartial light distribution patterns, such as a high-beam lightdistribution pattern (for driving) formed by superimposing a hot-zonepartial light distribution pattern, a middle-zone partial lightdistribution pattern (diffused more than the hot-zone partial lightdistribution pattern), and a wide-zone partial light distributionpattern (diffused more than the middle-zone partial light distributionpattern). Furthermore, the vehicle lighting fixture 301 cannot changethe light intensity of a particular partial light distribution patternout of the plurality of partial light distribution patterns inaccordance with the condition surrounding the vehicle.

SUMMARY

The presently disclosed subject matter was devised in view of these andother problems and features in association with the conventional art.According to an aspect of the presently disclosed subject matter, therecan be provided a vehicle lighting fixture configured to formpredetermined light distribution patterns (for example, a high-beam(driving) light distribution pattern and a low-beam (passing) lightdistribution pattern) by superimposing a plurality of partial lightdistribution patterns, wherein the vehicle lighting fixture can change alight intensity of at least one partial light distribution pattern outof the plurality of partial light distribution patterns.

According to another aspect of the presently disclosed subject matter, avehicle lighting fixture can be configured to form a predetermined lightdistribution pattern by superimposing N partial light distributionpatterns wherein N is a natural number of 2 or more. The vehiclelighting fixture can include a light intensity changing unit configuredto change a light intensity of at least one partial light distributionpattern out of the N partial light distribution patterns.

With the vehicle lighting fixture according to the above-describedaspect, the predetermined light distribution pattern (for example, ahigh-beam (driving) light distribution pattern and a low-beam (passing)light distribution pattern) can be made appropriate for the conditionssurrounding the vehicle body (namely, the running conditions). This canbe achieved by the light intensity changing unit configured to change alight intensity of at least one partial light distribution pattern outof the N partial light distribution patterns.

According to another aspect of the presently disclosed subject matter,the vehicle lighting fixture according to the above-mentioned aspect canbe configured to form a plurality of predetermined light distributionpatterns, and when one light distribution pattern among the plurality ofpredetermined light distribution patterns is selected on the basis of amanual operation or an automatic operation based on information from asensor installed in a vehicle body, the light intensity changing unitcan change a light intensity of at least one partial light distributionpattern among the N partial light distribution patterns so as to formthe one light distribution pattern selected manually or automatically.

In the vehicle lighting fixture with the above configuration, thepredetermined light distribution pattern (for example, a high-beam(driving) light distribution pattern and a low-beam (passing) lightdistribution pattern) can be made appropriate for the conditionssurrounding the vehicle body, or the running conditions, manually orautomatically in accordance with the conditions surrounding the vehicle.

According to another aspect of the presently disclosed subject matter,the vehicle lighting fixture according to the above-mentioned aspectconfigured to form a predetermined light distribution pattern bysuperimposing N partial light distribution patterns wherein N is anatural number of 2 or more can include: N optical fibers providedcorresponding to the respective N partial light distribution patterns; Nlaser light sources provided corresponding to the respective N opticalfibers; a plurality of diffractive optical elements providedcorresponding to the respective N laser light sources; an actuatorprovided corresponding to each one of the N laser light sources andconfigured to dispose any one of the plurality of diffractive opticalelements corresponding to the one of the N laser light sources in anoptical path of laser light from the one laser light source; and alighting unit configured to form the predetermined light distributionpattern with the laser light propagating through the N optical fibers.In this vehicle lighting fixture, when each one of the plurality ofdiffractive optical elements is disposed in the optical path of laserlight from corresponding one of the laser light sources, the one of theplurality of diffractive optical elements can be configured to deflectthe laser light from the corresponding one of the laser light sourcestoward respective incident end faces of the N optical fibers at disperseratios different from each other by diffracting the laser light from thelaser light source. The actuator can be configured to switch over eachone of the diffractive optical elements to be disposed in the opticalpath of laser light of the corresponding one of the laser light sourcesfor each laser light source so that an output of laser light exitingthrough an output end face of at least one optical fiber out of the Noptical fibers increases, to thereby change the light intensity of atleast one partial light distribution pattern out of the N partial lightdistribution patterns.

The vehicle lighting fixture according to the above-described aspect isconfigured to form predetermined light distribution patterns (forexample, a high-beam (driving) light distribution pattern and a low-beam(passing) light distribution pattern) by superimposing a plurality ofpartial light distribution patterns. Further, the vehicle lightingfixture can change the light intensity of at least one partial lightdistribution pattern out of the plurality of partial light distributionpatterns. As a result, the predetermined light distribution pattern (forexample, a high-beam (driving) light distribution pattern or a low-beam(passing) light distribution pattern) can be made appropriate for theconditions surrounding the vehicle (namely, the running condition).

This can be achieved by switching over the diffractive optical elementto be disposed in the optical path of laser light of the laser lightsource for each laser light source so that an output of laser lightexiting through the output end face of at least one optical fiber out ofthe N optical fibers increases, whereby the laser light with therelatively increased output can form a particular partial lightdistribution pattern.

Furthermore, with the above-described vehicle lighting fixture, withoutchanging the outputs of laser light from the respective laser lightsources (i.e., with the outputs of laser light from the respective laserlight sources being maintained), at least one partial light distributionpattern can be changed in terms of light intensity.

This is because the diffractive optical element to be disposed in theoptical path of laser light of the laser light source is switched overto another for each laser light source, thereby changing the lightintensity of the particular partial light distribution pattern.

According to another aspect of the presently disclosed subject matter,the vehicle lighting fixture according to the above-mentioned aspect canbe configured to form the plurality of predestined light distributionpatterns, and when a particular light distribution pattern among theplurality of predetermined light distribution patterns is selected onthe basis of a manual operation or an automatic operation based oninformation from a sensor installed in a vehicle, the actuator canswitch over the diffractive optical element to be disposed in theoptical path of the laser light of the laser light source for each laserlight source so as to form the particular light distribution patternselected manually or automatically.

The vehicle lighting fixture according to the above-described aspect isconfigured to manually or automatically form the predetermined lightdistribution pattern (for example, a high-beam (driving) lightdistribution pattern and a low-beam (passing) light distributionpattern) that can be made appropriate for the conditions surrounding thevehicle (namely, the running condition).

According to another aspect of the presently disclosed subject matter,the vehicle lighting fixture according to any of the above-mentionedaspects is configured such that the diffractive optical elements caneach be any one of a holographic optical element (HOE) and a blazeddiffractive optical element.

In the vehicle lighting fixture with the above configuration, the laserlight from each of the laser light sources can be deflected with highefficiency.

BRIEF DESCRIPTION OF DRAWINGS

These and other characteristics, features, and advantages of thepresently disclosed subject matter will become clear from the followingdescription with reference to the accompanying drawings, wherein:

FIG. 1 is a schematic diagram illustrating a configuration of aconventional vehicle lighting fixture disclosed in Japanese PatentApplication Laid-Open No. 2013-016277 (or US2014/0168940A1 correspondingto the Japanese publication);

FIG. 2 is a schematic diagram illustrating a configuration of a vehiclelighting fixture utilizing a coupler/distributer made in accordance withprinciples of the presently disclosed subject matter;

FIG. 3A is a view illustrating an exemplary high-beam light distributionpattern P_(Hi) formed by a vehicle lighting fixture 100 on a virtualvertical screen assumed to be disposed in front of a vehicle body,approximately 25 m away from the vehicle front face, and FIG. 3B is aview illustrating an exemplary low-beam light distribution patternP_(Lo);

FIG. 4 is a schematic diagram illustrating a lighting unit 40;

FIG. 5 is a perspective view illustrating the lighting unit 40;

FIG. 6 is a front view illustrating the lighting unit 40;

FIG. 7 is a cross-sectional view of the lighting unit of FIG. 6 takenalong line A-A;

FIG. 8 is a perspective view including the cross-sectional view of FIG.7 illustrating the lighting unit of FIG. 6 taken along line A-A;

FIG. 9 is a perspective view illustrating an optical deflector 201utilizing a 2-D optical scanner (fast resonant and slow staticcombination);

FIG. 10A is a schematic diagram illustrating the state in which firstpiezoelectric actuators 203 and 204 are not applied with a voltage, andFIG. 10B is a schematic diagram illustrating the state in which they areapplied with a voltage;

FIG. 11A is a schematic diagram illustrating the state in which secondpiezoelectric actuators 205 and 206 are not applied with a voltage, andFIG. 11B is a schematic diagram illustrating the state in which they areapplied with a voltage;

FIG. 12A is a diagram illustrating the maximum swing angle of a mirrorpart 202 around a first axis X1, and FIG. 12B is a diagram illustratingthe maximum swing angle of the mirror part 202 around a second axis X2;

FIGS. 13A, 13B, and 13C are a front view, a top plan view, and a sideview of a wavelength conversion member 18, respectively;

FIG. 14A is a graph showing the relationship between a mechanical swingangle (half angle) of the mirror part 202 around the first axis X1 andthe drive voltage to be applied to the first piezoelectric actuator 203and 204, and FIG. 14B is a graph showing the relationship between amechanical swing angle (half angle) of the mirror part 202 around thesecond axis X2 and the drive voltage to be applied to the secondpiezoelectric actuators 205 and 206;

FIG. 15 is a table summarizing the conditions to be satisfied in orderto change the scanning regions A_(Wide), A_(Mid), and A_(Hot) when thedistances between each of the optical deflectors 201 _(Wide), 201_(Mid), and 201 _(Hot) (the center of the mirror part 202) and thewavelength conversion member 18 are the same (or substantially the same)as each other;

FIG. 16A is a diagram for illustrating the “L” and “βh_max” illustratedin FIG. 15A, and FIG. 16B is a diagram for illustrating the “S,”“βv_max,” and L illustrated in FIG. 15B;

FIG. 17 is a schematic diagram illustrating an example in which thedistance between each of the optical deflectors 201 _(Wide), 201 _(Mid),and 201 _(Hot) (the center of the mirror part 202) and the wavelengthconversion member 18;

FIG. 18 shows tables summarizing the conditions to be satisfied in orderto change the sizes of the scanning regions A_(Wide), A_(Mid), andA_(Hot) when the drive voltage to be applied to each of the opticaldeflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) is the same (orsubstantially the same) as each other;

FIG. 19 is a longitudinal cross-sectional view illustrating a modifiedexample of the lighting unit 40;

FIG. 20A is a schematic longitudinal cross-sectional view illustrating acoupler/distributer 70, and FIG. 20B is a cross-sectional view of thecoupler/distributer 70 of FIG. 20A taken along line A1-A1;

FIG. 21 is a schematic perspective view illustrating a semiconductorlaser LD (LD_(LL1), LD_(LL2), and LD_(LL3));

FIG. 22A is a schematic diagram illustrating an example of diffractiveoptical elements 80 _(DO1-1) to 80 _(DO1-3), and FIG. 22B is a schematicdiagram illustrating another example of diffractive optical elements 80_(DO1-1) to 80 _(DO1-3);

FIG. 23 is a schematic diagram illustrating the state in which laserlight rays Ray_(LL1) is dispersed by diffraction at the diffractiveoptical element 80 _(DO1) (80 _(DO1-1) to 80 _(DO1-3));

FIG. 24 is a schematic diagram illustrating the relationship amongoptical fibers 36 _(Mid) and 36 _(Hot), diffractive optical element 80_(DO1), laser light source 74 _(LL1), etc.;

FIG. 25 is a diagram illustrating an example of shining light B_(1/3),B_(1/3), and B_(1/3) formed (reproduced) by diffraction by means of thediffractive optical element 80 _(DO1) (80 _(DO1-1) to 80 _(DO1-3));

FIG. 26 is a schematic diagram illustrating the state in which laserlight rays Ray_(LL2) is dispersed by diffraction at the diffractiveoptical element 80 _(DO2) (80 _(DO2-1) to 80 _(DO2-3));

FIG. 27 is a diagram illustrating an example of shining light B_(1/3),B_(1/3), and B_(1/3) formed (reproduced) by diffraction by means of thediffractive optical element 80 _(DO2) (80 _(DO2-1) to 80 _(DO2-3));

FIG. 28 is a schematic diagram illustrating the state in which laserlight rays Ray_(LL3) is dispersed by diffraction at the diffractiveoptical element 80 _(DO3) (80 _(DO3-1) to 80 _(DO3-3));

FIG. 29 is a diagram illustrating an example of shining light B_(1/3),B_(1/3), and B_(1/3) formed (reproduced) by diffraction by means of thediffractive optical element 80 _(DO3) (80 _(DO3-1) to 80 _(DO3-3));

FIG. 30A is a diagram illustrating the fundamental concept ofreproduction by a holographic optical element, and FIG. 30B is a partialenlarged cross-sectional view illustrating the diffractive opticalelement 80 _(DO1) to 80 _(DO3) constituted as a blazed diffractiveoptical element;

FIG. 31 is a functional block diagram representing the functionalconfiguration of the coupler/distributer 70;

FIG. 32 is a flow chart showing the basic action of thecoupler/distributer 70;

FIG. 33A is a table summarizing the relationship between the lightdistribution selected manually or automatically and the diffractiveoptical element 80 _(DO1) to 80 _(DO3) used when that light distributionis selected, and FIG. 33B is a table summarizing the relationshipbetween the light distribution selected manually or automatically andthe light scattering ratio when that light distribution is selected;

FIG. 34A is a schematic diagram illustrating a specific example ofcondenser lens 78 (78 _(Wide), 78 _(Mid), and 78 _(Hot)), FIG. 34B is aschematic diagram illustrating the state in which, when parallel lightrays to the optical axis of the condenser lens 78 (78 _(Wide), 78_(Mid), and 78 _(Hot)) are incident on the first to third condenserlenses 78 _(Wide), 78 _(Mid), and 78 _(Hot), the light rays arecondensed and incident on the light incident surface of an opticalfiber; and FIG. 34C is a schematic diagram illustrating the state inwhich, when light rays tilted by 10 degrees with respect to the opticalaxis are incident on the first to third condenser lenses 78 _(Wide), 78_(Mid), and 78 _(Hot), the light rays are condensed and incident on thelight incident surface of the optical fiber; and

FIG. 35 is a schematic diagram illustrating the configuration of avehicle lighting fixture 100A as a modified example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

A description will now be made below to vehicle lighting fixtures of thepresently disclosed subject matter utilizing a coupler/distributer withreference to the accompanying drawings in accordance with exemplaryembodiments.

In the specification, the term “hot-zone” member/part can mean amember/part for use in forming a hot-zone partial light distributionpattern (with highest intensity), the term “middle-zone” member/part canmean a member/part for use in forming a middle-zone partial lightdistribution pattern (diffused more than the hot-zone partial lightdistribution pattern), and the term “wide-zone” member/part can mean amember/part for use in forming a wide-zone partial light distributionpattern (diffused more than the middle-zone partial light distributionpattern), unless otherwise specified.

FIG. 2 is a schematic diagram illustrating a configuration of a vehiclelighting fixture 100 utilizing a coupler/distributer 70 made inaccordance with the principles of the presently disclosed subjectmatter.

As illustrated in FIG. 2, the vehicle lighting fixture 100 can includethe coupler/distributer 70, a wide-zone optical fiber 36 _(Wide), amiddle-zone optical finger 36 _(Mid), a hot-zone optical fiber 36_(Hot), a lighting unit 40, etc. The vehicle lighting fixture 100 canfurther include a housing 22 and an outer lens 16 to define a lightingchamber 24. The lighting unit 40 can be disposed within the lightingchamber 24 together with an extension 12. Reference numeral 26 denotes amember serving as a fixing mechanism and an optical axis adjustmentmechanism. The coupler/distributer 70 can be accommodated in a casing 30together with a control circuit 28 to be modularized therewith.

Each of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) can becoupled at its incident end to corresponding one of optical fibercoupling parts 72 _(Wide), 72 _(Mid), and 72 _(Hot) of thecoupler/distributer 70. Furthermore, each of the optical fibers 36_(Wide), 36 _(Mid), and 36 _(Hot) can be coupled at its output end tothe lighting unit 40.

The lighting unit 40 can be configured to form a high-beam lightdistribution pattern P_(Hi), as illustrated in FIG. 3A, using laserlight propagated through the respective optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot). FIG. 3A illustrates an exemplary high-beam lightdistribution pattern P_(Hi) formed by the vehicle lighting fixture 100on a virtual vertical screen assumed to be disposed in front of avehicle body (approximately 25 m away from the vehicle front face). Thehigh-beam light distribution pattern P_(Hi) can be formed bysuperimposing the respective partial light distribution patterns P_(Hi)_(_) _(Wide), P_(Hi) _(_) _(Mid), and P_(Hi) _(_) _(Hot).

The high-beam light distribution pattern P_(Hi) can correspond to the“predetermined light distribution pattern formed by superimposing Npartial light distribution patterns” as defined in the presentlydisclosed subject matter. The wide-zone optical fiber 36 _(Wide),middle-zone optical finger 36 _(Mid), and hot-zone optical fiber 36_(Hot) can correspond to the “N optical fibers provided corresponding tothe respective N partial light distribution patterns” as defined in thepresently disclosed subject matter. The lighting unit 40 can correspondto the “lighting unit configured to form the predetermined lightdistribution pattern with the laser light propagating through the Noptical fibers” as defined in the presently disclosed subject matter. InFIG. 2, N is 3, for example, which is not limitative and may be anatural number of 2 or more.

The above-described configuration is not limitative, and the lightingunit 40 can be configured to form a low-beam light distribution patternP_(Lo), as illustrated in FIG. 3B, using the laser light propagatedthrough the respective optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot). FIG. 3B illustrates an exemplary low-beam light distributionpattern P_(Lo) formed by the vehicle lighting fixture 100 on the virtualvertical screen by superimposing the respective partial lightdistribution patterns P_(Lo) _(_) _(Wide), P_(Lo) _(_) _(Mid), andP_(Lo) _(_) _(Hot).

The lighting unit 40 can be configured, as illustrated in FIGS. 4 to 8,as a direct projection type lighting unit. The lighting unit 40 caninclude three optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot)each including a mirror part 202, a wavelength conversion member 18, aprojection lens assembly 20, etc. The three optical deflectors 201_(Wide), 201 _(Mid), and 201 _(Hot) can be provided corresponding to thethree optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) (output endsthereof). The wavelength conversion member 18 can include three scanningregions A_(Wide), A_(Mid), and A_(Hot) (see FIG. 4) providedcorresponding to the three optical deflectors 201 _(Wide), 201 _(Mid),and 201 _(Hot). Partial light intensity distributions can be formedwithin the respective scanning regions A_(Wide), A_(Mid), and A_(Hot),and can be projected through the projection lens assembly 20 serving asan optical system for forming the high-beam light distribution patternP_(Hi) (or the low-beam light distribution pattern P_(Lo)).

As illustrated in FIG. 7, the projection lens assembly 20, thewavelength conversion member 18, and the optical deflectors 201 (201_(Wide), 201 _(Mid), and 201 _(Hot)) can be disposed in this order alonga reference axis AX (or referred to as an optical axis) extending in, ingeneral, the front-to-rear direction of a vehicle body.

The lighting unit 40 can further include an optical fiber holder 46. Theoptical fiber holder 46 can be disposed to surround the reference axisAX and can hold the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot)(output ends thereof) with a posture tilted in such a manner that laserlight rays Ray_(Wide), Ray_(Mid), and Ray_(Hot) are directed rearwardand toward the reference axis AX, as illustrated in FIG. 7.

Specifically, the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot)(or the output ends thereof) can be disposed by being fixed to theoptical fiber holder 46 in the following manner.

As illustrated in FIG. 6, the optical fiber holder 46 can be configuredto include a tubular part 48 extending in the reference axis AX, andextension parts 50U, 50D, 50L, and 50R each radially extending from theouter peripheral face at its upper, lower, left, or right part in anupper, lower, left, or right direction perpendicular to the referenceaxis AX. Specifically, the respective extension parts 50U, 50D, 50L, and50R can be inclined rearward to the tip ends thereof, as illustrated inFIG. 7. Between the adjacent extension parts, there can be formed a heatdissipation part 54 (heat dissipation fin), as illustrated in FIG. 6.

As illustrated in FIG. 7, the wide-zone optical fiber 36 _(Wide) can befixed to the tip end of the extension part 50D with a posture tilted sothat the laser light rays Ray_(Wide) is directed to a rearward andobliquely upward direction. Similarly, the middle-zone optical fiber 36_(Mid) can be fixed to the tip end of the extension part 50U with aposture tilted so that the laser light rays Ray_(Mid) is directed to arearward and obliquely downward direction. Similarly, the hot-zoneoptical fiber 36 _(Hot) can be fixed to the tip end of the extensionpart SOL with a posture tilted so that the laser light rays Ray_(Hot) isdirected to a rearward and obliquely rightward direction.

The lighting unit 40 can further include a lens holder 56 to which theprojection lens assembly 20 (lenses 20A to 20D) is fixed. The lensholder 56 can be screwed at its rear end to the opening of the tubularpart 48 so as to be fixed to the tubular part 48.

A condenser lens 14 can be disposed in front of each of the opticalfibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) (output end faces thereof).The laser light rays Ray_(Wide), Ray_(Mid), and Ray_(Hot) can be outputfrom the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) (output endfaces thereof) and condensed by the respective condenser lenses 14 (forexample, collimated) to be incident on the respective mirror parts 202of the optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot).

The optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) can beconfigured by, for example, an MEMS scanner. The driving system of theoptical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) is notlimited to a particular system, and examples thereof may include apiezoelectric system, an electrostatic system, and an electromagneticsystem.

The piezoelectric system used in the optical deflector is not limited toa particular system, and examples thereof may include a one-dimensionalnonresonance/one-dimensional resonance type, a two-dimensionalnonresonance type, and a two-dimensional resonance type.

The following exemplary embodiment may employ the one-dimensionalnonresonance/one-dimensional resonance type (2-D optical scanner (fastresonant and slow static combination)) of optical deflector using thepiezoelectric system, as one example.

FIG. 9 is a perspective view illustrating the optical deflector 201utilizing a 2-D optical scanner (fast resonant and slow staticcombination).

As illustrated in FIG. 9, the optical deflector 201 can include themirror part 202 (also called as MEMS mirror), first piezoelectricactuators 203 and 204, a movable frame 212, second piezoelectricactuators 205 and 206, and a base 215. The first piezoelectric actuators203 and 204 can drive the mirror part 202 via torsion bars 211 a and 211b. The movable frame 212 can support the first piezoelectric actuators203 and 204. The second piezoelectric actuators 205 and 206 can drivethe movable frame 212. The base 215 can support the second piezoelectricactuators 205 and 206.

The mirror part 202 can be formed in a circle shape and the torsion bars211 a and 211 b can be connected to the mirror part 202 so as to extendoutward from both ends of the mirror part 202. The first piezoelectricactuators 203 and 204 can be formed in a semi-circle shape so as tosurround the mirror part 202 while disposed with a gap between them.Furthermore, the first piezoelectric actuators 203 and 204 can becoupled to each other with the torsion bars 211 a and 211 b interposedtherebetween at their respective ends. The movable frame 212 can bedisposed to surround the mirror part 202 and the first piezoelectricactuators 203 and 204. The first piezoelectric actuators 203 and 204 canbe coupled to and supported by the movable frame 212 at respective outercentral portions of the semi-circle (arc) shape.

The movable frame 212 can have a rectangular shape and include a pair ofsides disposed in a direction perpendicular to the directions of thetorsion bars 211 a and 211 b, at which the movable frame 212 can becoupled to the respective tip ends of the second piezoelectric actuators205 and 206 opposite to each other with the movable frame 212 interposedtherebetween. The base 215 can include a supporting base part 214 formedthereon so as to surround the movable frame 212 and the secondpiezoelectric actuators 205 and 206. In this configuration, the secondpiezoelectric actuators 205 and 206 can be coupled to and supported atrespective base ends thereof by the supporting base part 214.

The first piezoelectric actuators 203 and 204 each can include a singlepiezoelectric cantilever composed of a support 203 a, 204 a, a lowerelectrode 203 b, 204 b, a piezoelectric body 203 c, 204 c, and an upperelectrode 203 d, 204 d, as illustrated in FIG. 10A.

Further, as illustrated in FIG. 9, the second piezoelectric actuators205 and 206 each can include six piezoelectric cantilevers 205A to 205F,206A to 206F, which are coupled to adjacent ones thereof so as to befolded back at its end. As a result, the second piezoelectric actuators205 and 206 can be formed in an accordion shape as a whole. Each of thepiezoelectric cantilevers 205A to 205F and 206A to 206F can have thesame configuration as those of the piezoelectric cantilevers of thefirst piezoelectric actuators 203 and 204.

A description will now be given of the action of the mirror part 202(swing motion around a first axis X1).

FIGS. 10A and 10B each show the cross-sectional view of the part wherethe first piezoelectric actuators 203 and 204 are provided, while takenalong line A-A in FIG. 9. Specifically, FIG. 10A is a schematic diagramillustrating the state in which the first piezoelectric actuators 203and 204 are not applied with a voltage, and FIG. 10B is a schematicdiagram illustrating the state in which they are applied with a voltage.

As illustrated in FIG. 10B, voltages of +Vd and −Vd, which haverespective reversed polarity, can be applied to between the upperelectrode 203 d and the lower electrode 203 b of the first piezoelectricactuator 203 and between the upper electrode 204 d and the lowerelectrode 204 b of the first piezoelectric actuator 204, respectively.As a result, they can be deformed while being bent in respectiveopposite directions.

This bent deformation can rotate the torsion bar 211 b in such a stateas illustrated in FIG. 10B. The torsion bar 211 a can receive the samerotation. Upon rotation of the torsion bars 211 a and 211 b, the mirrorpart 201 can be swung around the first axis X1 with respect to themovable frame 212.

A description will now be given of the action of the mirror part 202(swing motion around a second axis X2). Note that the second axis X2 isperpendicular to the first axis X1 at the center (center of gravity) ofthe mirror part 202.

FIG. 11A is a schematic diagram illustrating the state in which thesecond piezoelectric actuators 205 and 206 are not applied with avoltage, and FIG. 11B is a schematic diagram illustrating the state inwhich they are applied with a voltage.

As illustrated in FIG. 11B, when the second piezoelectric actuator 206is applied with a voltage, the odd-numbered piezoelectric cantilevers206A, 206C, and 206E from the movable frame 212 side can be deformed andbent upward while the even-numbered piezoelectric cantilevers 206B,206D, and 206F can be deformed and bent downward. As a result, thepiezoelectric actuator 206 as a whole can be deformed with a largerangle (angular variation) accumulated by the magnitudes of therespective bent deformation of the piezoelectric cantilevers 206A to206F. The second piezoelectric actuator 205 can also be driven in thesame manner. This angular variation of the second piezoelectricactuators 205 and 206 can cause the movable frame 212 (and the mirrorpart 202 supported by the movable frame 212) to rotate with respect tothe base 215 around the second axis X2 perpendicular to the first axisX1.

A single support formed by processing a silicon substrate can constitutea mirror part support for the mirror part 202, the torsion bars 211 aand 211 b, supports for the first piezoelectric actuators 203 and 204,the movable frame 212, supports for the second piezoelectric actuators205 and 206, and the supporting base part 214 on the base 215.Furthermore, the base 215 can be formed from a silicon substrate, andtherefore, it can be integrally formed from the above single support byprocessing a silicon substrate. The technique of processing such asilicon substrate can employ those described in, for example, JapanesePatent Application Laid-Open No. 2008-040240, which is herebyincorporated in its entirety by reference. There can be a gap betweenthe mirror part 202 and the movable frame 212, so that the mirror part202 can be swung around the first axis X1 with respect to the movableframe 212 within a predestined angle range. Furthermore, there can be agap between the movable frame 212 and the base 215, so that the movableframe 212 (and together with the mirror part 202 supported by themovable frame 212) can be swung around the second axis X2 with respectto the base 215 within a predetermined angle range.

The optical deflector 201 can include electrode sets 207 and 208 toapply a drive voltage to the respective piezoelectric actuators 203 to206.

The electrode set 207 can include an upper electrode pad 207 a, a firstupper electrode pad 207 b, a second upper electrode pad 207 c, and acommon lower electrode 207 d. The upper electrode pad 207 a can beconfigured to apply a drive voltage to the first piezoelectric actuator203. The first upper electrode pad 207 b can be configured to apply adrive voltage to the odd-numbered piezoelectric cantilevers 205A, 205C,and 205E of the second piezoelectric actuator 205. The second upperelectrode pad 207 c can be configured to apply a drive voltage to theeven-numbered piezoelectric cantilevers 205B, 205D, and 205F of thesecond piezoelectric actuator 205. The common lower electrode 207 d canbe used as a lower electrode common to the upper electrode pads 207 a to207 c.

Similarly thereto, the electrode set 208 can include an upper electrodepad 208 a, a first upper electrode pad 208 b, a second upper electrodepad 208 c, and a common lower electrode 208 d. The upper electrode pad208 a can be configured to apply a drive voltage to the firstpiezoelectric actuator 204. The first upper electrode pad 208 b can beconfigured to apply a drive voltage to the odd-numbered piezoelectriccantilevers 206A, 206C, and 206E of the second piezoelectric actuator206. The second upper electrode pad 208 c can be configured to apply adrive voltage to the even-numbered piezoelectric cantilevers 206B, 206D,and 206F of the second piezoelectric actuator 206. The common lowerelectrode 208 d can be used as a lower electrode common to the upperelectrode pads 208 a to 208 c.

In the present exemplary embodiment, the first piezoelectric actuator203 can be applied with a first AC voltage as a drive voltage, while thefirst piezoelectric actuator 204 can be applied with a second AC voltageas a drive voltage, wherein the first AC voltage and the second ACvoltage can be different from each other in phase, such as a sinusoidalwave with an opposite phase or shifted phase. In this case, an ACvoltage with a frequency close to a mechanical resonance frequency(first resonance point) of the mirror part 202 including the torsionbars 211 a and 211 b can be applied to resonantly drive the firstpiezoelectric actuators 203 and 204. This can cause the mirror part 202to be reciprocately swung around the first axis X1 with respect to themovable frame 212, so that the laser light rays from the optical fibers36 _(Wide), 36 _(Mid), and 36 _(Hot) (or the output end faces thereof)and incident on the mirror part 202 can scan in a first direction (forexample, horizontal direction).

A third AC voltage can be applied to each of the second piezoelectricactuators 205 and 206 as a drive voltage. In this case, an AC voltagewith a frequency equal to or lower than a predetermined value that issmaller than a mechanical resonance frequency (first resonance point) ofthe movable frame 212 including the mirror part 202, the torsion bars211 a and 211 b, and the first piezoelectric actuators 203 and 204 canbe applied to nonresonantly drive the second piezoelectric actuators 205and 206. This can cause the mirror part 202 to be reciprocately swungaround the second axis X2 with respect to the base 215, so that thelaser light rays from the optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) (or the output end faces thereof) and incident on the mirror part202 can scan in a second direction (for example, vertical direction).

The optical deflector 201 utilizing a 2-D optical scanner (fast resonantand slow static combination) can be arranged so that the first axis X1is contained in a vertical plane and the second axis X2 is contained ina horizontal plane. With this arrangement, a predetermined lightdistribution pattern (two-dimensional image corresponding to therequired predetermined light distribution pattern) being wide in thehorizontal direction and narrow in the vertical direction for use in avehicular headlight can be easily formed (drawn).

Specifically, the optical deflector 201 utilizing a 2-D optical scanner(fast resonant and slow static combination) can be configured such thatthe maximum swing angle of the mirror part 202 around the first axis X1is larger than the maximum swing angle of the mirror part 202 around thesecond axis X2. For example, since the reciprocal swing of the mirrorpart 202 around the first axis X1 is caused due to the resonancedriving, the maximum swing angle of the mirror part 202 around the firstaxis X1 ranges from 10 degrees to 20 degrees as illustrated in FIG. 12A.On the contrary, since the reciprocal swing of the mirror part 202around the second axis X2 is caused due to the nonresonance driving, themaximum swing angle of the mirror part 202 around the second axis X2becomes about 7 degrees as illustrated in FIG. 12B. As a result, theabove-described arrangement of the optical deflector 201 utilizing a 2-Doptical scanner (fast resonant and slow static combination) can easilyform (draw) a predetermined light distribution pattern (two-dimensionalimage corresponding to the required predetermined light distributionpattern) being wide in the horizontal direction and narrow in thevertical direction for use in a vehicular headlight.

As described above, by driving the respective piezoelectric actuators203 to 206, the laser light rays from the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (or the output end faces thereof) and incident onthe mirror part 202 can scan in a two dimensional manner (for example,in the horizontal and vertical directions).

As illustrated in FIG. 8, the optical deflectors 201 _(Wide), 201_(Mid), and 201 _(Hot) with the above-described configuration can bedisposed to surround the reference axis AX and be closer to thereference axis AX than the optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) (output ends thereof) so that the laser light rays output fromthe optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) (output endfaces thereof) can be incident on the corresponding mirror parts 202 ofthe optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) andreflected by the same to be directed to the corresponding scanningregions A_(Wide), A_(Mid), and A_(Hot), respectively.

Specifically, the optical deflectors 201 _(Wide), 201 _(Mid), and 201_(Hot) can be secured to an optical deflector holder 58 as follows.

The optical deflector holder 58 can have a square pyramid shapeprojected forward, and its front face can be composed of an upper face58U, a lower face 58D, a left face 58L, and a right face 58R (not shownin the drawings), as illustrated in FIG. 8.

The wide-zone optical deflector 201 _(Wide) can be secured to the lowerface 58D of the square pyramid face while being tilted so that themirror part 202 thereof is positioned in an optical path of the laserlight rays Ray_(Wide) output from the wide-zone optical fiber 36 _(Wide)(the output end faces thereof). Similarly thereto, the middle-zoneoptical deflector 201 _(Mid) can be secured to the upper face 58U of thesquare pyramid face while being tilted so that the mirror part 202thereof is positioned in an optical path of the laser light raysRay_(Mid) output from the middle-zone optical fiber 36 _(Mid) (theoutput end faces thereof). Similarly thereto, the hot-zone opticaldeflector 201 _(Hot) can be secured to the left face 58L (when viewedfrom front) of the square pyramid face while being tilted so that themirror part 202 thereof is positioned in an optical path of the laserlight rays Ray_(Hot) output from the hot-zone optical fiber 36 _(Hot)(the output end faces thereof).

The optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) each canbe arranged so that the first axis X1 is contained in a vertical planeand the second axis X2 is contained in a horizontal plane. As a result,the above-described arrangement of the optical deflectors 201 _(Wide),201 _(Mid), and 201 _(Hot) can easily form (draw) a predetermined lightdistribution pattern (two-dimensional image corresponding to therequired predetermined light distribution pattern) being wide in thehorizontal direction and narrow in the vertical direction for use in avehicular headlight.

The wide-zone optical deflector 201 _(Wide) can draw a firsttwo-dimensional image on the wide-zone scanning region A_(Wide) with thelaser light rays Ray_(Wide) two-dimensionally scanning in the horizontaland vertical directions by the mirror part 202 thereof, to thereby forma first light intensity distribution on the wide-zone scanning regionA_(Wide).

Specifically, the vehicle lighting fixture 100 can include a MEMS powercircuit 68 _(Wide) and a CPU 88, as illustrated in FIG. 31. In responseto a command from the CPU 88, the MEMS power circuit 68 _(Wide) canapply first and second AC voltages to the first piezoelectric actuators203 and 204 of the wide-zone optical deflector 201 _(Wide), to therebyresonantly drive the first piezoelectric actuators 203 and 204. As aresult, the mirror part 202 of the wide-zone optical deflector 201_(Wide) can be reciprocately swung around the first axis X1.Furthermore, the MEMS power circuit 68 _(Wide) can apply a third ACvoltage to the second piezoelectric actuators 205 and 206 of thewide-zone optical deflector 201 _(Wide), to thereby nonresonantly drivethe second piezoelectric actuators 205 and 206. As a result, the mirrorpart 202 of the wide-zone optical deflector 201 _(Wide) can bereciprocately swung around the second axis X2. In this manner, the laserlight rays incident on the mirror part 202 can scan two-dimensionally(in the horizontal and vertical direction) to thereby form the firstlight intensity distribution on the wide-zone scanning region A_(Wide).

The middle-zone optical deflector 201 _(Mid) can draw a secondtwo-dimensional image on the middle-zone scanning region A_(Mid) withthe laser light rays Ray_(Mid) two-dimensionally scanning in thehorizontal and vertical directions by the mirror part 202 thereof insuch a manner that the second two-dimensional image overlaps the firsttwo-dimensional image in part, to thereby form a second light intensitydistribution on the middle-zone scanning region A_(Mid) with a higherlight intensity than that of the first light intensity distribution.

Specifically, the vehicle lighting fixture 100 can include a MEMS powercircuit 68 _(Mid) as illustrated in FIG. 31. In response to a commandfrom the CPU 88, the MEMS power circuit 68 _(Mid) can apply first andsecond AC voltages to the first piezoelectric actuators 203 and 204 ofthe middle-zone optical deflector 201 _(Mid), to thereby resonantlydrive the first piezoelectric actuators 203 and 204. As a result, themirror part 202 of the middle-zone optical deflector 201 _(Mid) can bereciprocately swung around the first axis X1. Furthermore, the MEMSpower circuit 68 _(Mid) can apply a third AC voltage to the secondpiezoelectric actuators 205 and 206 of the middle-zone optical deflector201 _(Mid), to thereby nonresonantly drive the second piezoelectricactuators 205 and 206. As a result, the mirror part 202 of themiddle-zone optical deflector 201 _(Mid) can be reciprocately swungaround the second axis X2. In this manner, the laser light rays incidenton the mirror part 202 can scan two-dimensionally (in the horizontal andvertical direction) to thereby form the second light intensitydistribution on the middle-zone scanning region A_(Mid).

As illustrated in FIG. 4, the middle-zone scanning region A_(Mid) can besmaller than the wide-zone scanning region A_(Wide) in size and overlappart of the wide-zone scanning region A_(Wide). As a result of theoverlapping, the overlapped middle-zone scanning region A_(Mid) can havethe relatively higher light intensity distribution.

The hot-zone optical deflector 201 _(Hot) can draw a thirdtwo-dimensional image on the hot-zone scanning region A_(Hot) with thelaser light rays Ray_(Hot) two-dimensionally scanning in the horizontaland vertical directions by the mirror part 202 thereof in such a mannerthat the third two-dimensional image overlaps the first and secondtwo-dimensional images in part, to thereby form a third light intensitydistribution on the hot-zone scanning region A_(Hot) with a higher lightintensity than that of the second light intensity distribution.

Specifically, the vehicle lighting fixture 100 can include a MEMS powercircuit 68 _(Hot) as illustrated in FIG. 31. In response to a commandfrom the CPU 88, the MEMS power circuit 68 _(Hot) can apply first andsecond AC voltages to the first piezoelectric actuators 203 and 204 ofthe hot-zone optical deflector 201 _(Hot), to thereby resonantly drivethe first piezoelectric actuators 203 and 204. As a result, the mirrorpart 202 of the hot-zone optical deflector 201 _(Hot) can bereciprocately swung around the first axis X1. Furthermore, the MEMSpower circuit 68 _(Hot) can apply a third AC voltage to the secondpiezoelectric actuators 205 and 206 of the hot-zone optical deflector201 _(Hot), to thereby nonresonantly drive the second piezoelectricactuators 205 and 206. As a result, the mirror part 202 of the hot-zoneoptical deflector 201 _(Hot) can be reciprocately swung around thesecond axis X2. In this manner, the laser light rays incident on themirror part 202 can scan two-dimensionally (in the horizontal andvertical direction) to thereby form the third light intensitydistribution on the hot-zone scanning region A_(Hot).

As illustrated in FIG. 4, the hot-zone scanning region A_(Hot) can besmaller than the middle-zone scanning region A_(Mid) in size and overlappart of the middle-zone scanning region A_(Mid). As a result of theoverlapping, the overlapped hot-zone scanning region A_(Hot) can havethe relatively higher light intensity distribution.

The shape of the illustrated scanning regions A_(Wide), A_(Mid), andA_(Hot) in FIG. 4 is a rectangular outer shape, but it is notlimitative. The outer shape thereof can be a circle, an oval, or othershapes.

FIGS. 13A, 13B, and 13C are a front view, a top plan view, and a sideview of the wavelength conversion member 18, respectively.

The illustrated wavelength conversion member 18 can be configured to bea rectangular plate with a horizontal length of 18 mm and a verticallength of 9 mm. The wavelength conversion member 18 can also be referredto as a phosphor panel.

The wavelength conversion member 18 can be a rectangular plate orlaminate configured to receive and convert at least part of the laserlight rays, which two-dimensionally scan (in the horizontal and verticaldirections) by means of the optical deflectors 201 _(Wide), 201 _(Mid),and 201 _(Hot), to light rays with different wavelength.

As illustrated in FIGS. 7 and 8, the lighting unit 40 can include aphosphor holder 52 which can close the rear end opening of the tubularpart 48. The wavelength conversion member 18 can be secured to thephosphor holder 52. Specifically, the phosphor holder 52 can have anopening 52 a formed therein and the wavelength conversion member 18 canbe secured to the periphery of the opening 52 a of the phosphor holder52 at its outer periphery of the rear surface 18 a thereof. The positionof the wavelength conversion member 18 can be substantially at the focalpoint F of the projection lens 20 in a state where the wavelengthconversion member 18 covers the opening 52 a.

Examples of the wavelength conversion member 18 may include a phosphorplate (or laminate) excited by blue laser to emit yellow light. When thelaser light rays Ray_(Wide), Ray_(Mid), and Ray_(Hot) output from theoptical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) (output end facesthereof) are those in a blue wavelength region, the wavelengthconversion member 18 can be excited by the blue laser light raysRay_(Wide), Ray_(Mid), and Ray_(Hot) to thereby emit yellow light. Inother words, the blue laser light rays Ray_(Wide), Ray_(Mid), andRay_(Hot) can two dimensionally scan the wavelength conversion member 18(in the horizontal and vertical directions) by means of the opticaldeflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot), to draw atwo-dimensional image corresponding to the partial light distributionpatterns P_(Hi) _(_) _(Wide), P_(Hi) _(_) _(Mid), and P_(Hi) _(_) _(Hot)as a white image. The two-dimensional white image (pseudo-white image)can be formed (drawn) by color mixture of the original blue laser lightpassing through the wavelength conversion member 18 and the yellow lightemitted by the wavelength conversion member 18 as a result of excitationby the blue laser light.

As another example of the wavelength conversion member, a phosphor plate(or laminate) excited by near UV laser to emit three primary coloredlight rays, or red, green, and blue light. When the laser light raysRay_(Wide), Ray_(Mid), and Ray_(Hot) output from the optical fibers 36_(Wide), 36 _(Mid), and 36 _(Hot) (output end faces thereof) are thosein a near UV wavelength region, the wavelength conversion member 18 canbe excited by the near UV laser light rays Ray_(Wide), Ray_(Mid), andRay_(Hot) to thereby emit red, green, and blue light. In other words,the near UV laser light rays Ray_(Wide), Ray_(Mid), and Ray_(Hot) cantwo dimensionally scan the wavelength conversion member 18 (in thehorizontal and vertical directions) by means of the optical deflectors201 _(Wide), 201 _(Mid), and 201 _(Hot), to draw a two-dimensional imagecorresponding to the partial light distribution patterns P_(Hi) _(_)_(Wide), P_(Hi) _(_) _(Mid), and P_(Hi) _(_) _(Hot) as a white image.The two-dimensional white image (pseudo-white image) can be formed(drawn) by color mixture of the red, blue, and green light emitted bythe wavelength conversion member 18 as a result of excitation by thenear UV laser light.

The laser light rays Ray_(Wide), Ray_(Mid), and Ray_(Hot) output fromthe optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) (output endfaces thereof) can be condensed (or, for example, collimated) by thecondenser lens 14 to be incident on the respective mirror parts 202 ofthe optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot).

The projection lens 20 can be composed of a group of four lenses 20A to20D that have been aberration-corrected (have been corrected in terms ofthe field curvature) to provide a planar image formed, as illustrated inFIGS. 7 and 8. The lenses may also be color aberration-corrected. Then,the planar wavelength conversion member 18 can be disposed in alignmentwith the image plane.

The projection lens 20 composed of a group of plural lenses is notlimitative, and may be composed of a single aspheric lens withoutaberration correction (correction of the field curvature) to form aplanar image. In this case, the wavelength conversion member 18 shouldbe a curved one corresponding to the field curvature and disposed alongthe field curvature.

The focal point F of the projection lens 20 can be located at or nearthe wavelength conversion member 18. When the projection lens 20 is agroup of plural lenses, the projection lens 20 can remove the adverseeffect of the aberration on the high-beam light distribution patternP_(Hi) more than a single convex lens used. With this projection lens20, the planar wavelength conversion member 18 can be employed. This isadvantageous because the planar wavelength conversion member 18 can beproduced easier than a curved wavelength conversion member. Furthermore,this is advantageous because the planar wavelength conversion member 18can facilitate the drawing of a two-dimensional image thereon easierthan a curved wavelength conversion member.

The projection lens 20 can project the light intensity distributionformed in the wavelength conversion member 18 (three scanning regionsA_(Wide), A_(Mid), and A_(Hot)) forward to form the high-beam lightdistribution pattern P_(Hi) on a virtual vertical screen.

The wavelength conversion member 18 can be disposed to be confinedbetween the center line AX₂₀₂ of the mirror part 202 of the wide-zoneoptical deflector 201 _(Wide) at the maximum deflection angle βh_max(see FIG. 16A) and the center line AX₂₀₂ of the mirror part 202 of thewide-zone optical deflector 201 _(Wide) at the maximum deflection angleβv_max (see FIG. 16B). Specifically, the wavelength conversion member 18should be disposed to satisfy the following two formulas 1 and 2:tan(βh_max)≧L/d  (Formula 1), andtan(βv_max)≧S/d  (Formula 1),wherein L is ½ of a horizontal length of the wavelength conversionmember 18, S is ½ of a vertical length of the wavelength conversionmember 18, and d is the distance from the wavelength conversion member18 and the optical deflector 201 (mirror part 202).

A description will next be given of how to adjust the sizes (horizontallength and vertical length) of the scanning regions A_(Wide), A_(Mid),and A_(Hot).

The sizes (horizontal length and vertical length) of the scanningregions A_(Wide), A_(Mid), and A_(Hot) can be adjusted by changing theswinging ranges of the mirror parts 202 of the optical deflectors 201_(Wide), 201 _(Mid), and 201 _(Hot) around the first axis X1 and theswinging ranges of the mirror parts 202 of the optical deflectors 201_(Wide), 201 _(Mid), and 201 _(Hot) around the second axis X2. This canbe done by changing the first and second AC voltages to be applied tothe first piezoelectric actuators 203 and 204 and the third AC voltageto be applied to the second piezoelectric actuators 205 and 206 when thedistances between each of the optical deflectors 201 _(Wide), 201_(Mid), and 201 _(Hot) (the center of the mirror part 202) and thewavelength conversion member 18 are the same (or substantially the same)as each other. (See FIGS. 6 and 7.) The reasons therefore are asfollows.

Specifically, as illustrated in FIG. 14A, in the optical deflectors 201_(Wide), 201 _(Mid), and 201 _(Hot), the mechanical swing angle (halfangle, see the vertical axis) of the mirror part 202 around the firstaxis X1 is increased as the drive voltage (see the horizontal axis) tobe applied to the first piezoelectric actuators 203 and 204 isincreased. Furthermore, as illustrated in FIG. 14B, the mechanical swingangle (half angle, see the vertical axis) of the mirror part 202 aroundthe second axis X2 is increased as the drive voltage (see the horizontalaxis) to be applied to the second piezoelectric actuators 205 and 206 isincreased.

Thus, when the distances between each of the optical deflectors 201_(Wide), 201 _(Mid), and 201 _(Hot) (the center of the mirror part 202)and the wavelength conversion member 18 are the same (or substantiallythe same) as each other (see FIGS. 6 and 7), the sizes (horizontallength and vertical length) of the scanning regions A_(Wide), A_(Mid),and A_(Hot) can be adjusted by changing the first and second AC voltagesto be applied to the first piezoelectric actuators 203 and 204 and thethird AC voltage to be applied to the second piezoelectric actuators 205and 206, and thereby changing the swinging ranges of the mirror parts202 of the optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot)around the first axis X1 and the swinging ranges of the mirror parts 202of the optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) aroundthe second axis X2.

Next, a description will be given of a concrete adjustment example. Inthe following description, it is assumed that the distances between eachof the optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) (thecenter of the mirror part 202) and the wavelength conversion member 18are the same (or substantially the same) as each other and d=24.0 mm asillustrated in FIGS. 16A and 16B and the focal distance of theprojection lens 20 is 32 mm.

As shown in the row “WIDE” of the table of FIG. 15A, when 5.41 V_(pp) asa drive voltage is applied to the first piezoelectric actuators 203 and204 of the wide-zone optical deflector 201 _(Wide), the mechanical swingangle (half angle: γh_max) around the first axis X1 and the maximumdeflection angle (half angle: βh_max) are ±9.8 degrees and ±19.7degrees, respectively. In this case, the size (horizontal length) of thewide-zone scanning region A_(Wide) is adjusted to be ±8.57 mm.

The “L” and “βh_max” described in FIG. 15A represent the distance andthe angle shown in FIG. 16A. The “mirror mechanical half angle” (alsoreferred to as “mechanical half angle”) described in FIG. 15A means theangle at which the mirror part 202 actually moves, and represents anangle of the mirror part 202 with respect to the normal direction withthe sign “+” or “−.” The “mirror deflection angle” (also referred to as“optical half angle”) means the angle formed between the laser light(light rays) reflected by the mirror part and the normal direction ofthe mirror part 202, and also represents an angle of the mirror part 202with respect to the normal direction with the sign “+” or “−.” Accordingto the Fresnel's law, the optical half angle is twice the mechanicalhalf angle.

As shown in the row “WIDE” of the table of FIG. 15B, when 41.2 V_(pp) asa drive voltage is applied to the second piezoelectric actuators 205 and206 of the wide-zone optical deflector 201 _(Wide), the mechanical swingangle (half angle: γh_max) around the first axis X1 and the maximumdeflection angle (half angle: βh_max) are ±4.3 degrees and ±8.6 degrees,respectively. In this case, the size (vertical length) of the wide-zonescanning region A_(Wide) is adjusted to be ±3.65 mm.

The “S” and “βv_max” described in FIG. 15B represent the distance andthe angle shown in FIG. 16B, respectively.

As described above, by applying 5.41 V_(pp) as a drive voltage (thefirst and second AC voltages) to the first piezoelectric actuators 203and 204 of the wide-zone optical deflector 201 _(Wide), and applying41.2 V_(pp) as a drive voltage (the third AC voltage) to the secondpiezoelectric actuators 205 and 206 of the wide-zone optical deflector201 _(Wide), and thereby changing the swinging range of the mirror part202 of the wide-zone optical deflector 201 _(Wide) around the first axisX1 and the swinging range of the mirror part 202 of the wide-zoneoptical deflector 201 _(Wide) around the second axis X2, the size(horizontal length) of the wide-zone scanning region A_(Wide) can beadjusted to be ±8.57 mm and the size (vertical length) of the wide-zonescanning region A_(Wide) can be adjusted to be ±3.65 mm to form arectangular shape with the horizontal length of ±8.57 mm and thevertical length of ±3.65 mm.

The light intensity distribution formed in the wide-zone scanning regionA_(Wide) with the above-described dimensions can be projected forwardthrough the projection lens 20 to thereby form the wide-zone partiallight distribution pattern P_(Hi) _(_) _(Wide) with a rectangle of thewidth of ±15 degrees in the horizontal direction and the width of ±6.5degrees in the vertical direction on the virtual vertical screen.

As shown in the row “MID” of the table of FIG. 15A, when 2.31 V_(pp) asa drive voltage is applied to the first piezoelectric actuators 203 and204 of the middle-zone optical deflector 201 _(Mid), the mechanicalswing angle (half angle: γh_max) around the first axis X1 and themaximum deflection angle (half angle: βh_max) are ±5.3 degrees and ±11.3degrees, respectively. In this case, the size (horizontal length) of themiddle-zone scanning region A_(Mid) is adjusted to be ±4.78 mm.

As shown in the row “WIDE” of the table of FIG. 15B, when 24.4 V_(pp) asa drive voltage is applied to the second piezoelectric actuators 205 and206 of the middle-zone optical deflector 201 _(Mid), the mechanicalswing angle (half angle: γh_max) around the first axis X1 and themaximum deflection angle (half angle: βh_max) are ±2.3 degrees and ±4.7degrees, respectively. In this case, the size (vertical length) of themiddle-zone scanning region A_(Mid) is adjusted to be ±1.96 mm.

As described above, by applying 2.31 V_(pp) as a drive voltage (thefirst and second AC voltages) to the first piezoelectric actuators 203and 204 of the middle-zone optical deflector 201 _(Mid), and applying24.4 V_(pp) as a drive voltage (the third AC voltage) to the secondpiezoelectric actuators 205 and 206 of the middle-zone optical deflector201 _(Mid), and thereby changing the swinging range of the mirror part202 of the middle-zone optical deflector 201 _(Mid) around the firstaxis X1 and the swinging range of the mirror part 202 of the middle-zoneoptical deflector 201 _(Mid) around the second axis X2, the size(horizontal length) of the middle-zone scanning region A_(Mid) can beadjusted to be ±4.78 mm and the size (vertical length) of themiddle-zone scanning region A_(Mid) can be adjusted to be ±1.96 mm toform a rectangular shape with the horizontal length of ±4.78 mm and thevertical length of ±1.96 mm.

The light intensity distribution formed in the middle-zone scanningregion A_(Mid) with the above-described dimensions can be projectedforward through the projection lens 20 to thereby form the middle-zonepartial light distribution pattern P_(Hi) _(_) _(Mid) with a rectangleof the width of ±8.5 degrees in the horizontal direction and the widthof ±3.5 degrees in the vertical direction on the virtual verticalscreen.

As shown in the row “HOT” of the table of FIG. 15A, when 0.93 V_(pp) asa drive voltage is applied to the first piezoelectric actuators 203 and204 of the hot-zone optical deflector 201 _(Hot), the mechanical swingangle (half angle: γh_max) around the first axis X1 and the maximumdeflection angle (half angle: βh_max) are ±2.3 degrees and ±4.7 degrees,respectively. In this case, the size (horizontal length) of the hot-zonescanning region A_(Hot) is adjusted to be ±1.96 mm.

As shown in the row “HOT” of the table of FIG. 15B, when 13.3 V_(pp) asa drive voltage is applied to the second piezoelectric actuators 205 and206 of the hot-zone optical deflector 201 _(Hot), the mechanical swingangle (half angle: γh_max) around the first axis X1 and the maximumdeflection angle (half angle: βh_max) are ±1.0 degrees and ±2.0 degrees,respectively. In this case, the size (vertical length) of the hot-zonescanning region A_(Hot) is adjusted to be ±0.84 mm.

As described above, by applying 0.93 V_(pp) as a drive voltage (thefirst and second AC voltages) to the first piezoelectric actuators 203and 204 of the hot-zone optical deflector 201 _(Hot), and applying 13.3V_(pp) as a drive voltage (the third AC voltage) to the secondpiezoelectric actuators 205 and 206 of the hot-zone optical deflector201 _(Hot), and thereby changing the swinging range of the mirror part202 of the hot-zone optical deflector 201 _(Hot) around the first axisX1 and the swinging range of the mirror part 202 of the hot-zone opticaldeflector 201 _(Hot) around the second axis X2, the size (horizontallength) of the hot-zone scanning region A_(Hot) can be adjusted to be±1.96 mm and the size (vertical length) of the hot-zone scanning regionA_(Hot) can be adjusted to be ±0.84 mm to form a rectangular shape withthe horizontal length of ±1.96 mm and the vertical length of ±0.84 mm.

The light intensity distribution formed in the hot-zone scanning regionA_(Hot) with the above-described dimensions can be projected forwardthrough the projection lens 20 to thereby form the hot-zone partiallight distribution pattern P_(Hi) _(_) _(Hot) with a rectangle of thewidth of ±3.5 degrees in the horizontal direction and the width of ±1.5degrees in the vertical direction on the virtual vertical screen.

Thus, when the distances between each of the optical deflectors 201_(Wide), 201 _(Mid), and 201 _(Hot) (the center of the mirror part 202)and the wavelength conversion member 18 are the same (or substantiallythe same) as each other (see FIGS. 6 and 7), the sizes (horizontallength and vertical length) of the scanning regions A_(Wide), A_(Mid),and A_(Hot) can be adjusted by changing the first and second AC voltagesto be applied to the first piezoelectric actuators 203 and 204 and thethird AC voltage to be applied to the second piezoelectric actuators 205and 206, and thereby changing the swinging ranges of the mirror parts202 of the optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot)around the first axis X1 and the swinging ranges of the mirror parts 202of the optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) aroundthe second axis X2.

A description will next be given of another technique of adjusting thesizes (horizontal length and vertical length) of the scanning regionsA_(Wide), A_(Mid), and A_(Hot).

When the drive voltages to be applied to the respective opticaldeflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) are the same (orsubstantially the same) as each other, the sizes (horizontal length andvertical length) of the scanning regions A_(Wide), A_(Mid), and A_(Hot)can be adjusted by changing the distances between each of the opticaldeflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) (the center of themirror part 202) and the wavelength conversion member 18.

Next, a description will be given of a concrete adjustment example. Inthe following description, it is assumed that the drive voltages to beapplied to the respective optical deflectors 201 _(Wide), 201 _(Mid),and 201 _(Hot) are the same as each other and the focal distance of theprojection lens 20 is 32 mm.

For example, as shown in the row “WIDE” of the table of FIG. 18A, whenthe distance between the wide-zone optical deflector 201 _(Wide) (thecenter of the mirror part 202) and the wavelength conversion member 18is set to 24.0 mm and 5.41 V_(pp) as a drive voltage is applied to thefirst piezoelectric actuators 203 and 204 of the wide-zone opticaldeflector 201 _(Wide), the mechanical swing angle (half angle: γh_max)around the first axis X1 and the maximum deflection angle (half angle:βh_max) are ±9.8 degrees and ±19.7 degrees, respectively. In this case,the size (horizontal length) of the wide-zone scanning region A_(Wide)is adjusted to be ±8.57 mm.

The “L” and “d,” and “βh_max” described in FIG. 18A represent thedistance and the angle shown in FIG. 16A, respectively.

Then, as shown in the row “WIDE” of the table of FIG. 18B, when thedistance between the wide-zone optical deflector 201 _(Wide) (the centerof the mirror part 202) and the wavelength conversion member 18 is setto 24.0 mm and 41.2 V_(pp) as a drive voltage is applied to the secondpiezoelectric actuators 205 and 206 of the wide-zone optical deflector201 _(Wide), the mechanical swing angle (half angle: γh_max) around thefirst axis X1 and the maximum deflection angle (half angle: βh_max) are±4.3 degrees and ±8.6 degrees, respectively. In this case, the size(vertical length) of the wide-zone scanning region A_(Wide) is adjustedto be ±3.65 mm.

The “S” and “d,” and “βv_max” described in FIG. 18B represent thedistance and the angle shown in FIG. 16B, respectively.

As described above, by setting the distance between the wide-zoneoptical deflector 201 _(Wide) (the center of the mirror part 202) andthe wavelength conversion member 18 to 24.0 mm, the size (horizontallength) of the wide-zone scanning region A_(Wide) can be adjusted to be±8.57 mm and the size (vertical length) of the wide-zone scanning regionA_(Wide) can be adjusted to be ±3.65 mm to form a rectangular shape withthe horizontal length of ±8.57 mm and the vertical length of ±3.65 mm.

The light intensity distribution formed in the wide-zone scanning regionA_(Wide) with the above-described dimensions can be projected forwardthrough the projection lens 20 to thereby form the wide-zone partiallight distribution pattern P_(Hi) _(_) _(Wide) with a rectangle of thewidth of ±15 degrees in the horizontal direction and the width of ±6.5degrees in the vertical direction on the virtual vertical screen.

Next, as shown in the row “MID” of the table of FIG. 18A, when thedistance between the middle-zone optical deflector 201 _(Mid) (thecenter of the mirror part 202) and the wavelength conversion member 18is set to 13.4 mm and 5.41 V_(pp) as a drive voltage is applied to thefirst piezoelectric actuators 203 and 204 of the middle-zone opticaldeflector 201 _(Mid) as in the wide-zone optical deflector 201 _(Wide),the mechanical swing angle (half angle: γh_max) around the first axis X1and the maximum deflection angle (half angle: βh_max) are ±9.8 degreesand ±19.7 degrees, respectively, as in the wide-zone optical deflector201 _(Wide). However, the distance (13.4 mm) between the middle-zoneoptical deflector 201 _(Mid) (the center of the mirror part 202) and thewavelength conversion member 18 is set to be shorter than the distance(24.0 mm) between the wide-zone optical deflector 201 _(Wide) (thecenter of the mirror part 202) and the wavelength conversion member 18.Thus, the size (horizontal length) of the middle-zone scanning regionA_(Mid) is adjusted to be ±4.78 mm.

Then, as shown in the row “MID” of the table of FIG. 18B, when thedistance between the middle-zone optical deflector 201 _(Mid) (thecenter of the mirror part 202) and the wavelength conversion member 18is set to 13.4 mm and 41.2 V_(pp) as a drive voltage is applied to thesecond piezoelectric actuators 205 and 206 of the middle-zone opticaldeflector 201 _(Mid) as in the wide-zone optical deflector 201 _(Wide),the mechanical swing angle (half angle: γh_max) around the first axis X1and the maximum deflection angle (half angle: βh_max) are ±4.3 degreesand ±8.6 degrees, respectively, as in the wide-zone optical deflector201 _(Wide). However, the distance (13.4 mm) between the middle-zoneoptical deflector 201 _(Mid) (the center of the mirror part 202) and thewavelength conversion member 18 is set to be shorter than the distance(24.0 mm) between the wide-zone optical deflector 201 _(Wide) (thecenter of the mirror part 202) and the wavelength conversion member 18.Thus, the size (vertical length) of the middle-zone scanning regionA_(Mid) is adjusted to be ±1.96 mm.

As described above, by setting the distance between the middle-zoneoptical deflector 201 _(Mid) (the center of the mirror part 202) and thewavelength conversion member 18 to 13.4 mm, the size (horizontal length)of the middle-zone scanning region A_(Mid) can be adjusted to be ±4.78mm and the size (vertical length) of the middle-zone scanning regionA_(Mid) can be adjusted to be ±1.96 mm to form a rectangular shape withthe horizontal length of ±4.78 mm and the vertical length of ±1.96 mm.

The light intensity distribution formed in the middle-zone scanningregion A_(Mid) with the above-described dimensions can be projectedforward through the projection lens 20 to thereby form the middle-zonepartial light distribution pattern P_(Hi) _(_) _(Mid) with a rectangleof the width of ±8.5 degrees in the horizontal direction and the widthof ±3.6 degrees in the vertical direction on the virtual verticalscreen.

Next, as shown in the row “HOT” of the table of FIG. 18A, when thedistance between the hot-zone optical deflector 201 _(Hot) (the centerof the mirror part 202) and the wavelength conversion member 18 is setto 5.5 mm and 5.41 V_(pp) as a drive voltage is applied to the firstpiezoelectric actuators 203 and 204 of the hot-zone optical deflector201 _(Hot) as in the wide-zone optical deflector 201 _(Wide), themechanical swing angle (half angle: γh_max) around the first axis X1 andthe maximum deflection angle (half angle: βh_max) are ±9.8 degrees and±19.7 degrees, respectively, as in the wide-zone optical deflector 201_(Wide). However, the distance (5.5 mm) between the hot-zone opticaldeflector 201 _(Hot) (the center of the mirror part 202) and thewavelength conversion member 18 is set to be shorter than the distance(13.4 mm) between the middle-zone optical deflector 201 _(Mid) (thecenter of the mirror part 202) and the wavelength conversion member 18.Thus, the size (horizontal length) of the hot-zone scanning regionA_(Hot) is adjusted to be ±1.96 mm.

Then, as shown in the row “HOT” of the table of FIG. 18B, when thedistance between the hot-zone optical deflector 201 _(Hot) (the centerof the mirror part 202) and the wavelength conversion member 18 is setto 5.5 mm and 41.2 V_(pp) as a drive voltage is applied to the secondpiezoelectric actuators 205 and 206 of the hot-zone optical deflector201 _(Hot) as in the wide-zone optical deflector 201 _(Wide), themechanical swing angle (half angle: γh_max) around the first axis X1 andthe maximum deflection angle (half angle: βh_max) are ±4.3 degrees and±8.6 degrees, respectively, as in the wide-zone optical deflector 201_(Wide). However, the distance (5.5 mm) between the hot-zone opticaldeflector 201 _(Hot) (the center of the mirror part 202) and thewavelength conversion member 18 is set to be shorter than the distance(13.4 mm) between the middle-zone optical deflector 201 _(Mid) (thecenter of the mirror part 202) and the wavelength conversion member 18.Thus, the size (vertical length) of the hot-zone scanning region A_(Hot)is adjusted to be ±0.84 mm.

As described above, by setting the distance between the hot-zone opticaldeflector 201 _(Hot) (the center of the mirror part 202) and thewavelength conversion member 18 to 5.5 mm, the size (horizontal length)of the hot-zone scanning region A_(Hot) can be adjusted to be ±1.96 mmand the size (vertical length) of the hot-zone scanning region A_(Hot)can be adjusted to be ±0.84 mm to form a rectangular shape with thehorizontal length of ±1.96 mm and the vertical length of ±0.84 mm.

The light intensity distribution formed in the hot-zone scanning regionA_(Hot) with the above-described dimensions can be projected forwardthrough the projection lens 20 to thereby form the hot-zone partiallight distribution pattern P_(Hi) _(_) _(Hot) with a rectangle of thewidth of ±3.5 degrees in the horizontal direction and the width of ±1.5degrees in the vertical direction on the virtual vertical screen.

As described above, when the drive voltages to be applied to therespective optical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot)are the same (or substantially the same) as each other, the sizes(horizontal length and vertical length) of the scanning regionsA_(Wide), A_(Mid), and A_(Hot) can be adjusted by changing the distancesbetween each of the optical deflectors 201 _(Wide), 201 _(Mid), and 201_(Hot) (the center of the mirror part 202) and the wavelength conversionmember 18.

When the first and second AC voltages to be applied to the respectiveoptical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) arefeedback-controlled, the drive voltages applied to the respectiveoptical deflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) are notcompletely the same. Even in this case, the sizes (horizontal length andvertical length) of the scanning regions A_(Wide), A_(Mid), and A_(Hot)can be adjusted by changing the distance between each of the opticaldeflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) (the center of eachof the mirror parts 202) and the wavelength conversion member 18.

A description will next be given of still another technique of adjustingthe sizes (horizontal length and vertical length) of the scanningregions A_(Wide), A_(Mid), and A_(Hot).

It is conceivable that the sizes (horizontal length and vertical length)of the scanning regions A_(Wide), A_(Mid), and A_(Hot) can be adjustedby disposing a lens 66 between each of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (output end) and each of the optical deflectors201 _(Wide), 201 _(Mid), and 201 _(Hot) (between each of the opticaldeflectors 201 _(Wide), 201 _(Mid), and 201 _(Hot) and the wavelengthconversion member 18), as illustrated in FIG. 19. The lens 66 may be alens having a different focal distance.

FIG. 20A is a schematic longitudinal cross-sectional view illustrating acoupler/distributer 70, and FIG. 20B is a cross-sectional view of thecoupler/distributer 70 of FIG. 20A taken along line A1-A1.

As illustrated in FIGS. 20A and 20B, the coupler/distributer 70 caninclude optical fiber attaching parts 72 _(Wide), 72 _(Mid), and 72_(Hot) to which the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot)(input ends thereof) are attached respectively, first to third laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3), first to thirdcollimating lenses 76 _(LL1), 76 _(LL2), and 76 _(LL3), first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot), a plurality ofdiffraction optical elements 80 _(DO1), 80 _(DO2), and 80 _(DO3), anactuator (not illustrated), a casing 82, a casing heat dissipation part84 including a heat dissipation plate 84 a (heat dissipation fin), etc.

The first to third laser light sources 74 _(LL1), 74 _(LL2), and 74_(LL3) correspond to the “N laser light sources provided correspondingto the respective N optical fibers” as defined in the presentlydisclosed subject matter. The plurality of diffraction optical elements80 _(DO1), 80 _(DO2), and 80 _(DO3) correspond to the “plurality ofdiffractive optical elements provided corresponding to the respective Nlaser light sources” as defined in the presently disclosed subjectmatter. The example illustrated in FIG. 20A is a case where N is 3(three), which is not limitative and N may be a natural number of 3 ormore.

The optical fiber attaching parts 72 _(Wide), 72 _(Mid), and 72 _(Hot)can be secured to the front face of the casing 82. The first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) can be disposedclose to and behind the optical fiber attaching parts 72 _(Wide), 72_(Mid), and 72 _(Hot).

The casing heat dissipation part 84 including a heat dissipation plate84 a can be attached to the rear face of the casing 82, and the first tothird laser light sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) and thefirst to third collimating lenses 76 _(LL1), 76 _(LL2), and 76 _(LL3),can be secured to the casing heat dissipation part 84. Specifically, thecasing heat dissipation part 84 can include first to third through holesH1, H2, and H3 formed and extending in a first reference axis AX1, in asecond reference axis AX2, and in a third reference axis AX3,respectively. The first laser light source 74 _(LL1) and the firstcollimating lens 76 _(LL1) can be secured to the casing heat dissipationpart 84 while being inserted into the first through hole H1 formed inthe casing heat dissipation part 84 and extending in the first referenceaxis AX1. Similarly, the second laser light source 74 _(LL2) and thesecond collimating lens 76 _(LL2) can be secured to the casing heatdissipation part 84 while being inserted into the second through hole H2formed the casing heat dissipation part 84 and extending in the secondreference axis AX2. Also the third laser light source 74 _(LL3) and thethird collimating lens 76 _(LL3) can be secured to the casing heatdissipation part 84 while being inserted into the third through hole H3formed in the casing heat dissipation part 84 and extending in the thirdreference axis AX3.

The first to third laser light sources 74 _(LL1), 74 _(LL2), and 74_(LL3) can include semiconductor lasers LD_(LL1), LD_(LL2), andLD_(L0L3) housed in a cap, and LD output monitors PD_(LL1), PD_(LL2),and PD_(L0L3), such as monitoring photodiodes and the like.

FIG. 21 is a schematic perspective view of a semiconductor laser LD(LD_(LL1), LD_(LL2), and LD_(L0L3)).

As illustrated in FIG. 20, the semiconductor laser LD can be asemiconductor light-emitting element, such as a laser diode, configuredto emit laser light (linearly polarized light) in an TE mode in whichthe electric field component is parallel to the junction plane A (activeregion). Although the semiconductor laser can emit laser light in a TMmode in which the electric field component is perpendicular to thejunction plane A (active region), it can dominantly emit laser light ina TE mode with larger gain. The emission wavelength of such asemiconductor laser LD may fall within a blue region, and can be, forexample, 450 nm. Also, the emission wavelength of such a semiconductorlaser LD may fall within a near UV region, and can be, for example, 405nm.

The laser light sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) can bearranged in a dispersed state along the reference axes AX1 to AX3,respectively, as illustrated in FIG. 20A. This arrangement can improvethe heat dissipation property when compared with a case where laserlight sources are arranged in line in a dense manner.

The first diffraction optical element 80 _(DO1) can include a pluralityof diffraction optical elements 80 _(DO1-1) to 80 _(DO1-3).

The respective diffraction optical elements 80 _(DO1-1) to 80 _(DO1-3)can be arranged along the optical path (or the reference axis AX1) ofthe laser light rays Ray_(LL1) emitted from the first laser light source74 _(LL1) and collimated by the first collimating lens 76 _(LL1) asillustrated in FIG. 22A. Or as illustrated in FIG. 22B, they can bearranged circularly while they are secured to a rotary plate 86,although the arrangement of these elements is not limited to aparticular one. In FIG. 22B, the portion denoted by S may be a circularopening without any element or may be omitted.

The respective diffraction optical elements 80 _(DO1-1) to 80 _(DO1-3)can be moved by a not-illustrated actuator, such as a solenoid, to bedisposed in the optical path of the laser light rays Ray_(LL1) emittedfrom the first laser light source 74 _(LL1) and collimated by the firstcollimating lens 76 _(LL1) or outside of the optical path.

When the respective diffraction optical elements 80 _(DO1) to 80 _(DO3)are secured to the rotary plate 86, the rotary plate 86 can be rotatedand stopped by a not-illustrated actuator, such as a solenoid, so thatthe respective diffraction optical elements 80 _(DO1) to 80 _(DO3) aredisposed in the optical path of the laser light rays Ray_(LL1) emittedfrom the first laser light source 74 _(LL1) and collimated by the firstcollimating lens 76 _(LL1) or outside of the optical path.

When the respective diffraction optical elements 80 _(DO1) to 80 _(DO3)are disposed in the optical path of the laser light rays Ray_(LL1)emitted from the first laser light source 74 _(LL1) and collimated bythe first collimating lens 76 _(LL1), as illustrated in FIG. 23, theycan deflect the laser light rays Ray_(LL1) and direct them to the inputend faces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot)(strictly speaking, the first to third condenser lenses 78 _(Wide), 78_(Mid), and 78 _(Hot)) at respective different ratios (disperse ratio)due to the diffraction. In order to achieve this configuration, therespective diffraction optical elements 80 _(DO1-1) to 80 _(DO1-3) canbe configured by a holographic optical element (HOE). In anotherexemplary embodiment, they can be configured by a blazed diffractiveoptical element (DOE).

Specifically, they can be configured as follows.

The diffraction optical element 80 _(DO1-1) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL1) emitted from the first laser light source 74 _(LL1)and collimated by the first collimating lens 76 _(LL1) and direct themto the respective input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (strictly speaking, the respective first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) at a ratio of1/3:1/3:1/3 (disperse ratio) due to the diffraction.

Specifically, the diffraction optical element 80 _(DO1-1) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL1) emitted from the first laser light source74 _(LL1) and collimated by the first collimating lens 76 _(LL1) is usedas a reference light ray, direct the reproduced light rays to ranges ofrespective light receiving angles θ (effective lens incident angle) ofthe respective first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) at a ratio of 1/3:1/3:1/3 (disperse ratio) (see FIG. 24)and reproduce shining light B_(1/3), B_(1/3), and B_(1/3), asillustrated in FIG. 25.

The diffraction optical element 80 _(DO1-2) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL1) emitted from the first laser light source 74 _(LL1)and collimated by the first collimating lens 76 _(LL1) and direct themto the respective input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (strictly speaking, the respective first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) at a ratio of1/2:1/4:1/4 (disperse ratio) due to the diffraction. The diffractionoptical element 80 _(DO1-2) can have the same configuration as that ofthe diffraction optical element 80 _(DO1-1) except for the disperseratio.

Specifically, the diffraction optical element 80 _(DO1-2) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL1) emitted from the first laser light source74 _(LL1) and collimated by the first collimating lens 76 _(LL1) is usedas a reference light ray, direct the reproduced light rays to ranges ofrespective light receiving angles θ (effective lens incident angle) ofthe respective first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) at a ratio of 1/2:1/4:1/4 (disperse ratio) (see FIG. 24)and reproduce shining light B_(1/2), B_(1/4), and B_(1/4), asillustrated in FIG. 25.

The diffraction optical element 80 _(DO1-3) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL1) emitted from the first laser light source 74 _(LL1)and collimated by the first collimating lens 76 _(LL1) and direct themto the respective input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (strictly speaking, the respective first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) at a ratio of1/4:1/4:1/2 (disperse ratio) due to the diffraction. The diffractionoptical element 80 _(DO1-3) can have the same configuration as that ofthe diffraction optical element 80 _(DO1-1) except for the disperseratio.

Specifically, the diffraction optical element 80 _(DO1-3) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL1) emitted from the first laser light source74 _(LL1) and collimated by the first collimating lens 76 _(LL1) is usedas a reference light ray, direct the reproduced light rays to ranges ofrespective light receiving angles θ (effective lens incident angle) ofthe respective first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) at a ratio of 1/4:1/4:1/2 (disperse ratio) (see FIG. 24)and reproduce shining light B_(1/4), B_(1/4), and B_(1/2), asillustrated in FIG. 25.

The second diffraction optical element 80 _(DO2) can include a pluralityof diffraction optical elements 80 _(DO2-1) to 80 _(DO2-3).

The respective diffraction optical elements 80 _(DO2-1) to 80 _(DO2-3)can be arranged along the optical path (or the reference axis AX2) ofthe laser light rays Ray_(LL2) emitted from the second laser lightsource 74 _(LL2) and collimated by the second collimating lens 76 _(LL2)as illustrated in FIG. 22A. Or as illustrated in FIG. 22B, they can bearranged circularly while they are secured to a rotary plate 86,although the arrangement of these elements is not limited to aparticular one.

The respective diffraction optical elements 80 _(DO2-1) to 80 _(DO2-3)can be moved by a not-illustrated actuator, such as a solenoid, to bedisposed in the optical path of the laser light rays Ray_(LL2) emittedfrom the second laser light source 74 _(LL2) and collimated by thesecond collimating lens 76 _(LL2) or outside of the optical path.

When the respective diffraction optical elements 80 _(DO2-1) to 80_(DO2-3) are secured to the rotary plate 86, the rotary plate 86 can berotated and stopped by a not-illustrated actuator, such as a solenoid,so that the respective diffraction optical elements 80 _(DO2-1) to 80_(DO2-3) are disposed in the optical path of the laser light raysRay_(LL2) emitted from the second laser light source 74 _(LL2) andcollimated by the second collimating lens 76 _(LL2) or outside of theoptical path.

When the respective diffraction optical elements 80 _(DO2-1) to 80_(DO2-3) are disposed in the optical path of the laser light raysRay_(LL2) emitted from the second laser light source 74 _(LL2) andcollimated by the second collimating lens 76 _(LL2), as illustrated inFIG. 26, they can deflect the laser light rays Ray_(LL2) and direct themto the input end faces of the optical fibers 36 _(Wide), 36 _(Mid), and36 _(Hot) (strictly speaking, the first to third condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot)) at respective different ratios(disperse ratio) due to the diffraction. In order to achieve thisconfiguration, the respective diffraction optical elements 80 _(DO2-1)to 80 _(DO2-3) can be configured by a holographic optical element (HOE).In another exemplary embodiment, they can be configured by a blazeddiffractive optical element (DOE).

Specifically, they can be configured as follows.

The diffraction optical element 80 _(DO2-1) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2) and collimated by the second collimating lens 76 _(LL2) anddirect them to the respective input end faces of the optical fibers 36_(Wide), 36 _(Mid), and 36 _(Hot) (strictly speaking, the respectivefirst to third condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) ata ratio of 1/3:1/3:1/3 (disperse ratio) due to the diffraction.

Specifically, the diffraction optical element 80 _(DO2-1) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL2) emitted from the second laser lightsource 74 _(LL2) and collimated by the second collimating lens 76 _(LL2)is used as a reference light ray, direct the reproduced light rays toranges of respective light receiving angles θ (effective lens incidentangle) of the respective first to third condenser lenses 78 _(Wide), 78_(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 (disperse ratio) (seeFIG. 24) and reproduce shining light B_(1/3), B_(1/3), and B_(1/3), asillustrated in FIG. 27.

The diffraction optical element 80 _(DO2-2) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2) and collimated by the second collimating lens 76 _(LL2) anddirect them to the respective input end faces of the optical fibers 36_(Wide), 36 _(Mid), and 36 _(Hot) (strictly speaking, the respectivefirst to third condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) ata ratio of 1/2:1/4:1/4 (disperse ratio) due to the diffraction. Thediffraction optical element 80 _(DO2-2) can have the same configurationas that of the diffraction optical element 80 _(DO2-1) except for thedisperse ratio.

Specifically, the diffraction optical element 80 _(DO2-2) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL2) emitted from the second laser lightsource 74 _(LL2) and collimated by the second collimating lens 76 _(LL2)is used as a reference light ray, direct the reproduced light rays toranges of respective light receiving angles θ (effective lens incidentangle) of the respective first to third condenser lenses 78 _(Wide), 78_(Mid), and 78 _(Hot) at a ratio of 1/2:1/4:1/4 (disperse ratio) (seeFIG. 24) and reproduce shining light B_(1/2), B_(1/4), and B_(1/4), asillustrated in FIG. 27.

The diffraction optical element 80 _(DO2-3) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2) and collimated by the second collimating lens 76 _(LL2) anddirect them to the respective input end faces of the optical fibers 36_(Wide), 36 _(Mid), and 36 _(Hot) (strictly speaking, the respectivefirst to third condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) ata ratio of 1/4:1/4:1/2 (disperse ratio) due to the diffraction. Thediffraction optical element 80 _(DO2-3) can have the same configurationas that of the diffraction optical element 80 _(DO2-1) except for thedisperse ratio.

Specifically, the diffraction optical element 80 _(DO2-3) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL2) emitted from the second laser lightsource 74 _(LL2) and collimated by the second collimating lens 76 _(LL2)is used as a reference light ray, direct the reproduced light rays toranges of respective light receiving angles θ (effective lens incidentangle) of the respective first to third condenser lenses 78 _(Wide), 78_(Mid), and 78 _(Hot) at a ratio of 1/4:1/4:1/2 (disperse ratio) (seeFIG. 24) and reproduce shining light B_(1/4), B_(1/4), and B_(1/2), asillustrated in FIG. 27.

The third diffraction optical element 80 _(DO3) can include a pluralityof diffraction optical elements 80 _(DO3-1) to 80 _(DO3-3).

The respective diffraction optical elements 80 _(DO3-1) to 80 _(DO3-3)can be arranged along the optical path (or the reference axis AX3) ofthe laser light rays Ray_(LL3) emitted from the third laser light source74 _(LL3) and collimated by the third collimating lens 76 _(LL3) asillustrated in FIG. 22A. Or as illustrated in FIG. 22B, they can bearranged circularly while they are secured to a rotary plate 86,although the arrangement of these elements is not limited to aparticular one.

The respective diffraction optical elements 80 _(DO3-1) to 80 _(DO3-3)can be moved by a not-illustrated actuator, such as a solenoid, to bedisposed in the optical path of the laser light rays Ray_(LL3) emittedfrom the third laser light source 74 _(LL3) and collimated by the thirdcollimating lens 76 _(LL3) or outside of the optical path.

When the respective diffraction optical elements 80 _(DO3-1) to 80_(DO3-3) are secured to the rotary plate 86, the rotary plate 86 can berotated and stopped by a not-illustrated actuator, such as a solenoid,so that the respective diffraction optical elements 80 _(DO3-1) to 80_(DO3-3) are disposed in the optical path of the laser light raysRay_(LL3) emitted from the third laser light source 74 _(LL3) andcollimated by the third collimating lens 76 _(LL3) or outside of theoptical path.

When the respective diffraction optical elements 80 _(DO3-1) to 80_(DO3-3) are disposed in the optical path of the laser light raysRay_(LL3) emitted from the third laser light source 74 _(LL3) andcollimated by the third collimating lens 76 _(LL3), as illustrated inFIG. 28, they can deflect the laser light rays Ray_(LL3) and direct themto the input end faces of the optical fibers 36 _(Wide), 36 _(Mid), and36 _(Hot) (strictly speaking, the first to third condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot)) at respective different ratios(disperse ratio) due to the diffraction. In order to achieve thisconfiguration, the respective diffraction optical elements 80 _(DO3-1)to 80 _(DO2-3) can be configured by a holographic optical element (HOE).In another exemplary embodiment, they can be configured by a blazeddiffractive optical element (DOE).

Specifically, they can be configured as follows.

The diffraction optical element 80 _(DO3-1) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL3) emitted from the third laser light source 74 _(LL3)and collimated by the third collimating lens 76 _(LL3) and direct themto the respective input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (strictly speaking, the respective first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) at a ratio of1/3:1/3:1/3 (disperse ratio) due to the diffraction.

Specifically, the diffraction optical element 80 _(DO3-1) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL3) emitted from the third laser light source74 _(LL3) and collimated by the third collimating lens 76 _(LL3) is usedas a reference light ray, direct the reproduced light rays to ranges ofrespective light receiving angles θ (effective lens incident angle) ofthe respective first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) at a ratio of 1/3:1/3:1/3 (disperse ratio) (see FIG. 24)and reproduce shining light B_(1/3), B_(1/3), and B_(1/3), asillustrated in FIG. 29.

The diffraction optical element 80 _(DO3-2) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL3) emitted from the third laser light source 74 _(LL3)and collimated by the third collimating lens 76 _(LL3) and direct themto the respective input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (strictly speaking, the respective first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) at a ratio of1/2:1/4:1/4 (disperse ratio) due to the diffraction. The diffractionoptical element 80 _(DO3-2) can have the same configuration as that ofthe diffraction optical element 80 _(DO3-1) except for the disperseratio.

Specifically, the diffraction optical element 80 _(DO3-2) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL3) emitted from the third laser light source74 _(LL3) and collimated by the third collimating lens 76 _(LL3) is usedas a reference light ray, direct the reproduced light rays to ranges ofrespective light receiving angles θ (effective lens incident angle) ofthe respective first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) at a ratio of 1/2:1/4:1/4 (disperse ratio) (see FIG. 24)and reproduce shining light B_(1/2), B_(1/4), and B_(1/4), asillustrated in FIG. 29.

The diffraction optical element 80 _(DO3-3) can be configured as aholographic optical element that is configured to deflect the laserlight rays Ray_(LL3) emitted from the third laser light source 74 _(LL3)and collimated by the third collimating lens 76 _(LL3) and direct themto the respective input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot) (strictly speaking, the respective first to thirdcondenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot)) at a ratio of1/4:1/4:1/2 (disperse ratio) due to the diffraction. The diffractionoptical element 80 _(DO3-3) can have the same configuration as that ofthe diffraction optical element 80 _(DO3-1) except for the disperseratio.

Specifically, the diffraction optical element 80 _(DO3-3) can beconfigured as a holographic optical element that is configured to, whenthe laser light rays Ray_(LL3) emitted from the third laser light source74 _(LL3) and collimated by the third collimating lens 76 _(LL3) is usedas a reference light ray, direct the reproduced light rays to ranges ofrespective light receiving angles θ (effective lens incident angle) ofthe respective first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) at a ratio of 1/4:1/4:1/2 (disperse ratio) (see FIG. 24)and reproduce shining light B_(1/4), B_(1/4), and B_(1/2), asillustrated in FIG. 29.

The diffraction optical elements 80 _(DO1-1) to 80 _(DO1-3), 80 _(DO2-1)to 80 _(DO2-3), and 80 _(DO3-1) to 80 _(DO3-3) can each be a holographicoptical element made from a computer generated hologram (CGH).

The fundamental concept of reproduction by a holographic optical elementwill be described. FIG. 30A is a diagram illustrating the fundamentalconcept of reproduction by a holographic optical element

The holographic optical element 80 can be produced by irradiating ahologram base material with reference light and to-be-reproduced lightobtained by dividing coherent laser light, and recording theinterference state (holographic pattern) onto the base material. Theresulting holographic optical element 80 can be irradiated with only thereference light Ray1 to reproduce the to-be-reproduced light asinterference light with a holographic pattern (reproduced light).Specifically, the reference light Ray1 can impinge on the interferencepattern on the holographic optical element 80 to become reproduced lightRay2 to be converged to the output point P.

The holographic optical element 80 can be produced by CGH. In aconventional holographic recording method, interference fringes areformed by a wave front from an object and a reference wave front to beused for recording a complex amplitude distribution. The CGH is a methodof recording such a complex amplitude distribution only by calculatingthe above processes of the conventional holographic recording method.Specifically, a wave front reaching the surface of a holographic basematerial can be calculated on the basis of data of to-be-reproducedobject or wave front, and the calculated wave front or holographic baseimage can be displayed on an appropriate display device tophotographically reduce the size thereof to be used as a hologram. Thus,in principle, any wave forms of objects that can be mathematicallydescribed and have not been reproduced by the conventional holographicreproducing method can be recorded.

The diffraction optical elements 80 _(DO1-1) to 80 _(DO3), 80 _(DO2-1)to 80 _(DO2-3), and 80 _(DO3-1) to 80 _(DO3-3) can each be a blazeddiffraction optical element which can be configured by setting blazedangles θ1, θ2, and θ3, and blazed distances d1, d2, and d3, asillustrated in FIG. 30B. The adjustment of the blazed distance and/orblazed surface ratio can control the deflection (disperse light) of thelaser light rays Ray_(LL1), Ray_(LL2), and Ray_(LL3) emitted from therespective laser light sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) andcollimated by the respective collimating lenses 76 _(LL1), 76 _(LL2),and 76 _(LL3) in different directions at predetermined ratios (disperseratio).

A description will now be given of the functional configuration of thecoupler/distributer 70 with the above-described configuration withreference to the drawing.

FIG. 31 is a functional block diagram representing the functionalconfiguration of the coupler/distributer 70.

As illustrated in FIG. 31, the coupler/distributer 70 can include theCPU 88 that can control the entire operations. The CPU 88 can be coupledwith, via a bus, a headlamp switch 90; first to third actuators 92_(DO1), 92 _(DO2), and 92 _(DO3) corresponding to the first to thirddiffraction optical elements 80 _(DO1), 80 _(DO2), and 80 _(DO3); firstto third LD lighting circuits 94 _(LL1), 94 _(LL2), and 94 _(LL3),provided corresponding to the first to third laser light sources 74_(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasers LD_(LL1),LD_(LL2), and LD_(LL3)), for supplying a current to the respective laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3), (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)); a navigation system 96; a vehiclespeed sensor 98 a; a windshield wiper sensor 98 b; an ambient luminancesensor 98 c; first to third MEMS power circuits 68 _(Wide), 68 _(Mid),and 68 _(Hot); a program storage unit (not illustrated) configured tostore various programs executed by the CPU 88; a RAM (not illustrated)configured to serve to provide a work area and the like, etc. The firstto third actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) correspond to the“actuator provided corresponding to each one of the N laser lightsources and configured to dispose any one of the plurality ofdiffractive optical elements corresponding to the one of the N laserlight sources in an optical path of laser light from the one laser lightsource, for each laser light source” as defined in the presentlydisclosed subject matter.

The navigation system 96, vehicle speed sensor 98 a, windshield wipersensor 98 b, and ambient luminance sensor 98 c correspond to the “sensorinstalled in a vehicle” as defined in the presently disclosed subjectmatter.

Next, the operation of the coupler/distributer 70 with the aboveconfiguration will be described with reference to the drawings.

FIG. 32 is a flow chart showing the basic action of thecoupler/distributer 70. The following process may be achieved in such amanner that the CPU 88 can read various predetermined programs stored inthe program storage unit in the RAM and the like and execute the same.The following process can correspond to the “light intensity changingunit” as defined in the presently disclosed subject matter.

First, the headlamp switch 90 is turned on (step S10) to read lightdistribution setting information (step S12).

The light distribution setting information can be information indicatingthat the light distribution setting is automatically (AUTO) or manually(MANUAL) achieved, and can be stored in a storage device (notillustrated) connected to the CPU 88 upon operation of anautomatic/manual operation selector switch or the like installed in avehicle interior and operated by a driver or the like.

Next, according to an instruction from the CPU 88, the respective LDlighting circuits 94 _(LL1), 94 _(LL2), and 94 _(LL3) can control thefirst to third laser light sources 74 _(LL1), 74 _(LL2), and 74 _(LL3)(semiconductor lasers LD_(LL1), LD_(LL2), and LD_(LL3)) to emit laserlight with respective predetermined outputs (for example, maximumoutput) (step S14).

If the light distribution setting information is determined to indicatethe manual operation (step S16, MANUAL), the following processes can beexecuted in accordance with the manually selected light distribution.The processes may include “hot-zone important light distributionprocess” (step S18), “hot-zone brighter light distribution process”(step S20), “standard light distribution process” (step S22), “wide-zonebrighter light distribution process” (step S24), and “wide-zoneimportant light distribution process” (step S26). The “hot-zoneimportant light distribution”, “hot-zone brighter light distribution”,“standard light distribution”, “wide-zone brighter light distribution”,and “wide-zone important light distribution” correspond to the“plurality of predetermined light distribution patterns” as defined inthe presently disclosed subject matter.

Which light distribution has manually been selected can be determined onthe basis of, for example, a light distribution discrimination flag.

For example, if a driver manually operates a light distribution selectorswitch installed in a vehicle interior to select “hot-zone importantlight distribution,” the light distribution discrimination flag is setto include information indicating the “hot-zone important lightdistribution” manually selected by a driver, for example, as “L1.” Inthis case, it is determined that the manually selected lightdistribution is “hot-zone important light distribution” on the basis ofthe light distribution discrimination flag (step S16: L1), and the“hot-zone important light distribution process” can be performed (stepS18).

The “hot-zone important light distribution process” (step S18) cancontrol the respective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) toswitch over and move the diffraction optical elements to be disposedwithin the optical paths of laser light rays from the respective laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)) in such a manner that the outputs oflaser light rays output from the hot-zone optical fiber 36 _(Hot)(output end face thereof) become relatively high.

Specifically, in accordance with the instruction from the CPU 88, therespective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) can dispose thediffraction optical elements 80 _(DO1-3), 80 _(DO2-3), and 80 _(DO3-3)in the optical path of the laser light rays Ray_(LL1) emitted from thefirst laser light source 74 _(LL1), in the optical path of the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2), and in the optical path of the laser light rays Ray_(LL3)emitted from the third laser light source 74 _(LL3), respectively (seethe row of “L1: hot-zone important” in the table of FIG. 33A).

By doing so, the laser light rays Ray_(LL1) to Ray_(LL3) emitted fromthe respective laser light sources 74 _(LL1) to 74 _(LL3) can bedispersed at respective disperse ratios as shown in the row of “L1:hot-zone important” in the table of FIG. 33B.

For example, the laser light rays Ray_(LL1) emitted from the first laserlight source 74 _(LL1) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/4:1/4:1/2 due todiffraction at the diffraction optical element 80 _(DO1-3) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL2) emitted from the second laserlight source 74 _(LL2) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/4:1/4:1/2 due todiffraction at the diffraction optical element 80 _(DO2-3) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL3) emitted from the third laserlight source 74 _(LL3) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/4:1/4:1/2 due todiffraction at the diffraction optical element 80 _(DO3-3) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

The laser light rays having been incident on the respective input endfaces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) can bepropagated and output through the output end faces of the optical fibers36 _(Wide), 36 _(Mid), and 36 _(Hot) to enter the lighting unit 40, tothereby form a high-beam light distribution pattern P_(Hi) asillustrated in FIG. 3A.

Specifically, the laser light rays output from the respective output endfaces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) cantwo-dimensionally scan in the horizontal and vertical directions bymeans of the respective optical deflectors 201 _(Wide), 201 _(Mid), and201 _(Hot), to thereby form the first to third light intensitydistributions within the respective scanning regions A_(Wide), A_(Mid),and A_(Hot). The first to third light intensity distributions formed inthe respective scanning regions A_(Wide), A_(Mid), and A_(Hot) of thewavelength conversion member 18 can be projected forward through theprojection lens 20, so that the high-beam light distribution patternP_(Hi) can be formed on a virtual vertical screen by overlaying therespective partial light distribution patterns P_(Hi) _(_) _(Wide),P_(Hi) _(_) _(Mid), and P_(Hi) _(_) _(Hot).

In the present exemplary embodiment, the output ratios of the laserlight rays output from the respective output end faces of the wide-zone,middle-zone, and hot-zone optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) can be the relationship of 3/4:3/4:3/2 as shown in the table ofFIG. 33B. Specifically, the output of the laser light rays from theoutput end face of the hot-zone optical fiber 36 _(Hot) can becomerelatively high, for example, 3/2 of the maximum output. As a result,the light intensity of the hot-zone partial light distribution patternP_(Hi) _(_) _(Hot) can be changed, so that the high-beam lightdistribution pattern P_(Hi) can be formed as a hot-zone important lightdistribution pattern with the brighter hot-zone partial lightdistribution pattern P_(Hi) _(_) _(Hot). In this manner, the high-beamlight distribution pattern P_(Hi) can be formed to be made appropriatefor the conditions surrounding the vehicle body, or the runningcondition.

Furthermore, for example, if a driver manually operates a lightdistribution selector switch installed in a vehicle interior to select“hot-zone brighter light distribution,” the light distributiondiscrimination flag is set to include information indicating the“hot-zone brighter light distribution” manually selected by a driver,for example, as “L2.” In this case, it is determined that the manuallyselected light distribution is “hot-zone brighter light distribution” onthe basis of the light distribution discrimination flag (step S16: L2),and the “hot-zone brighter light distribution process” can be performed(step S20).

The “hot-zone brighter light distribution process” (step S20) cancontrol the respective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) toswitch over and move the diffraction optical elements to be disposedwithin the optical paths of laser light rays from the respective laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)) in such a manner that the outputs oflaser light rays output from the hot-zone optical fiber 36 _(Hot)(output end face thereof) become relatively high.

Specifically, in accordance with the instruction from the CPU 88, therespective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) can dispose thediffraction optical elements 80 _(DO1-3), 80 _(DO2-1), and 80 _(DO3-1)in the optical path of the laser light rays Ray_(LL1) emitted from thefirst laser light source 74 _(LL1), in the optical path of the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2), and in the optical path of the laser light rays Ray_(LL3)emitted from the third laser light source 74 _(LL3), respectively (seethe row of “L2: hot-zone brighter” in the table of FIG. 33A).

By doing so, the laser light rays Ray_(LL1) to Ray_(LL3) emitted fromthe respective laser light sources 74 _(LL1) to 74 _(LL3) can bedispersed at respective disperse ratios as shown in the row of “L2:hot-zone brighter” in the table of FIG. 33B.

For example, the laser light rays Ray_(LL1) emitted from the first laserlight source 74 _(LL1) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/4:1/4:1/2 due todiffraction at the diffraction optical element 80 _(DO1-3) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL2) emitted from the second laserlight source 74 _(LL2) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO2-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL3) emitted from the third laserlight source 74 _(LL3) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO3-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

The laser light rays having been incident on the respective input endfaces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) can bepropagated and output through the output end faces of the optical fibers36 _(Wide), 36 _(Mid), and 36 _(Hot) to enter the lighting unit 40, tothereby form a high-beam light distribution pattern P_(Hi) asillustrated in FIG. 3A.

In the present exemplary embodiment, the output ratios of the laserlight rays output from the respective output end faces of the wide-zone,middle-zone, and hot-zone optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) can be the relationship of 11/12:11/12:7/6 as shown in the tableof FIG. 33B. Specifically, the output of the laser light rays from theoutput end face of the hot-zone optical fiber 36 _(Hot) can becomerelatively high, for example, 7/6 of the maximum output. As a result,the light intensity of the hot-zone partial light distribution patternP_(Hi) _(_) _(Hot) can be changed, so that the high-beam lightdistribution pattern P_(Hi) can be formed as a hot-zone brighter lightdistribution pattern with the slightly brighter hot-zone partial lightdistribution pattern P_(Hi) _(_) _(Hot). In this manner, the high-beamlight distribution pattern P_(Hi) can be formed to be made appropriatefor the conditions surrounding the vehicle body, or the runningcondition.

Furthermore, for example, if a driver manually operates a lightdistribution selector switch installed in a vehicle interior to select“standard light distribution,” the light distribution discriminationflag is set to include information indicating the “standard lightdistribution” manually selected by a driver, for example, as “L3.” Inthis case, it is determined that the manually selected lightdistribution is “standard light distribution” on the basis of the lightdistribution discrimination flag (step S16: L3), and the “standard lightdistribution process” can be performed (step S22).

The “standard light distribution process” (step S22) can control therespective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) to switch overand move the diffraction optical elements to be disposed within theoptical paths of laser light rays from the respective laser lightsources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)) in such a manner that the outputs oflaser light rays output from the respective optical fiber 36 _(Wide), 36_(Mid), and 36 _(Hot) (output end faces thereof) become even.

Specifically, in accordance with the instruction from the CPU 88, therespective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) can dispose thediffraction optical elements 80 _(DO1-1), 80 _(DO2-1), and 80 _(DO3-1)in the optical path of the laser light rays Ray_(LL1) emitted from thefirst laser light source 74 _(LL1), in the optical path of the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2), and in the optical path of the laser light rays Ray_(LL3)emitted from the third laser light source 74 _(LL3), respectively (seethe row of “L3: standard” in the table of FIG. 33A).

By doing so, the laser light rays Ray_(LL1) to Ray_(LL3) emitted fromthe respective laser light sources 74 _(LL1) to 74 _(LL3) can bedispersed at respective disperse ratios as shown in the row of “L3:standard” in the table of FIG. 33B.

For example, the laser light rays Ray_(LL1) emitted from the first laserlight source 74 _(LL1) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO1-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL2) emitted from the second laserlight source 74 _(LL2) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO2-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL3) emitted from the third laserlight source 74 _(LL3) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO3-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

The laser light rays having been incident on the respective input endfaces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) can bepropagated and output through the output end faces of the optical fibers36 _(Wide), 36 _(Mid), and 36 _(Hot) to enter the lighting unit 40, tothereby form a high-beam light distribution pattern P_(Hi) asillustrated in FIG. 3A.

In the present exemplary embodiment, the output ratios of the laserlight rays output from the respective output end faces of the wide-zone,middle-zone, and hot-zone optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) can be the relationship of 3/3:3/3:3/3 as shown in the table ofFIG. 33B. Specifically, the outputs of the laser light rays from theoutput end faces of the respective optical fibers 36 _(Wide), 36 _(Mid),and 36 _(Hot) can become even. As a result, the light intensity of thehot-zone partial light distribution pattern P_(Hi) _(_) _(Hot) can bechanged. In this manner, the high-beam light distribution pattern P_(Hi)can be formed to be made appropriate for the conditions surrounding thevehicle body, or the running conditions.

Furthermore, for example, if a driver manually operates a lightdistribution selector switch installed in a vehicle interior to select“wide-zone brighter light distribution,” the light distributiondiscrimination flag is set to include information showing the “wide-zonebrighter light distribution” manually selected by a driver, for example,as “L4.” In this case, it is determined that the manually selected lightdistribution is “wide-zone brighter light distribution” on the basis ofthe light distribution discrimination flag (step S16: L4), and the“wide-zone brighter light distribution process” can be performed (stepS24).

The “wide-zone brighter light distribution process” (step S24) cancontrol the respective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) toswitch over and move the diffraction optical elements to be disposedwithin the optical paths of laser light rays from the respective laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)) in such a manner that the outputs oflaser light rays output from the wide-zone optical fiber 36 _(Wide)(output end face thereof) become relatively high.

Specifically, in accordance with the instruction from the CPU 88, therespective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) can dispose thediffraction optical elements 80 _(DO1-2), 80 _(DO2-1), and 80 _(DO3-1)in the optical path of the laser light rays Ray_(LL1) emitted from thefirst laser light source 74 _(LL1), in the optical path of the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2), and in the optical path of the laser light rays Ray_(LL3)emitted from the third laser light source 74 _(LL3), respectively (seethe row of “L4: wide-zone brighter” in the table of FIG. 33A).

By doing so, the laser light rays Ray_(LL1) to Ray_(LL3) emitted fromthe respective laser light sources 74 _(LL1) to 74 _(LL3) can bedispersed at respective disperse ratios as shown in the row of “L4:wide-zone brighter” in the table of FIG. 33B.

For example, the laser light rays Ray_(LL1) emitted from the first laserlight source 74 _(LL1) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/2:1/4:1/4 due todiffraction at the diffraction optical element 80 _(DO1-2) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL2) emitted from the second laserlight source 74 _(LL2) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO2-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL3) emitted from the third laserlight source 74 _(LL3) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/3:1/3:1/3 due todiffraction at the diffraction optical element 80 _(DO3-1) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

The laser light rays having been incident on the respective input endfaces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) can bepropagated and output through the output end faces of the optical fibers36 _(Wide), 36 _(Mid), and 36 _(Hot) to enter the lighting unit 40, tothereby form a high-beam light distribution pattern P_(Hi) asillustrated in FIG. 3A.

In the present exemplary embodiment, the output ratios of the laserlight rays output from the respective output end faces of the wide-zone,middle-zone, and hot-zone optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) can be the relationship of 7/6:11/12:11/12 as shown in the tableof FIG. 33B. Specifically, the output of the laser light rays from theoutput end face of the wide-zone optical fiber 36 _(Wide) can becomerelatively high, for example, 7/6 of the maximum output. As a result,the light intensity of the wide-zone partial light distribution patternP_(Hi) _(_) _(Wide) can be changed, so that the high-beam lightdistribution pattern P_(Hi) can be formed as a wide-zone brighter lightdistribution pattern with the slightly brighter wide-zone partial lightdistribution pattern P_(Hi) _(_) _(Wide). In this manner, the high-beamlight distribution pattern P_(Hi) can be formed to be made appropriatefor the conditions surrounding the vehicle body, or the runningconditions.

Furthermore, for example, if a driver manually operates a lightdistribution selector switch installed in a vehicle interior to select“wide-zone important light distribution,” the light distributiondiscrimination flag is set to include information showing the “wide-zoneimportant light distribution” manually selected by a driver, forexample, as “L5.” In this case, it is determined that the manuallyselected light distribution is “wide-zone important light distribution”on the basis of the light distribution discrimination flag (step S16:L5), and the “wide-zone important light distribution process” can beperformed (step S26).

The “wide-zone important light distribution process” (step S26) cancontrol the respective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) toswitch over and move the diffraction optical elements to be disposedwithin the optical paths of laser light rays from the respective laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)) in such a manner that the outputs oflaser light rays output from the wide-zone optical fiber 36 _(Wide)(output end face thereof) become relatively high.

Specifically, in accordance with the instruction from the CPU 88, therespective actuators 92 _(DO1), 92 _(DO2), and 92 _(DO3) can dispose thediffraction optical elements 80 _(DO1-2), 80 _(DO2-2), and 80 _(DO3-2)in the optical path of the laser light rays Ray_(LL1) emitted from thefirst laser light source 74 _(LL1), in the optical path of the laserlight rays Ray_(LL2) emitted from the second laser light source 74_(LL2), and in the optical path of the laser light rays Ray_(LL3)emitted from the third laser light source 74 _(LL3), respectively (seethe row of “L5: wide-zone important” in the table of FIG. 33A).

By doing so, the laser light rays Ray_(LL1) to Ray_(LL3) emitted fromthe respective laser light sources 74 _(LL1) to 74 _(LL3) can bedispersed at respective disperse ratios as shown in the row of “L5:wide-zone important” in the table of FIG. 33B.

For example, the laser light rays Ray_(LL1) emitted from the first laserlight source 74 _(LL1) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/2:1/4:1/4 due todiffraction at the diffraction optical element 80 _(DO1-2) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL2) emitted from the second laserlight source 74 _(LL2) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/2:1/4:1/4 due todiffraction at the diffraction optical element 80 _(DO2-2) and condensedby the condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) to beincident on the input end faces of the optical fibers 36 _(Wide), 36_(Mid), and 36 _(Hot).

Similarly, the laser light rays Ray_(LL3) emitted from the third laserlight source 74 _(LL3) can be directed to the condenser lenses 78_(Wide), 78 _(Mid), and 78 _(Hot) at a ratio of 1/2:1/4:1/4 due todiffraction at the diffraction optical element 80 _(DO3-2) and condensedby the condenser lenses 78 _(Wide), and 78 _(Hot) to be incident on theinput end faces of the optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot).

The laser light rays having been incident on the respective input endfaces of the optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) can bepropagated and output through the output end faces of the optical fibers36 _(Wide), 36 _(Mid), and 36 _(Hot) to enter the lighting unit 40, tothereby form a high-beam light distribution pattern P_(Hi) asillustrated in FIG. 3A.

In the present exemplary embodiment, the output ratios of the laserlight rays output from the respective output end faces of the wide-zone,middle-zone, and hot-zone optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) can be the relationship of 3/2:3/4:3/4 as shown in the table ofFIG. 33B. Specifically, the output of the laser light rays from theoutput end face of the wide-zone optical fiber 36 _(Wide) can becomerelatively high, for example, 3/2 of the maximum output. As a result,the light intensity of the wide-zone partial light distribution patternP_(Hi) _(_) _(Wide) can be changed, so that the high-beam lightdistribution pattern P_(Hi) can be formed as a wide-zone important lightdistribution pattern with the brighter wide-zone partial lightdistribution pattern P_(Hi) _(_) _(Wide). In this manner, the high-beamlight distribution pattern P_(Hi) can be formed to be made appropriatefor the conditions surrounding the vehicle body, or the runningconditions.

On the other hand, if the light distribution setting information isdetermined to show the automatic operation (step S16, AUTO), the AUTOcontrol light distribution process can be executed (step S28).

In the AUTO control light distribution process (step S28), navigationinformation, vehicle speed information, windshield wiper information,ambient luminance information, etc. can be read out from the navigationsystem 96, the vehicle speed sensor 98 a, the windshield wiper sensor 98b, the ambient luminance sensor 98 c, etc., respectively.

The light distribution can be automatically selected on the basis ofthese pieces of information, and in accordance with the automaticallyselected light distribution, the following processes can be executed.The processes may include the “hot-zone important light distributionprocess” (step S18), “hot-zone brighter light distribution process”(step S20), “standard light distribution process” (step S22), “wide-zonebrighter light distribution process” (step S24), and “wide-zoneimportant light distribution process” (step S26).

For example, if it is determined on the basis of the navigationinformation from the navigation system 96 that one's automobile on whichthe vehicle lighting fixture 100 is installed is running at high speed(highway driving), the “hot-zone important light distribution” can beautomatically selected and the “hot-zone important light distributionprocess” can be performed (step S18).

In another case, if it is determined on the basis of the navigationinformation from the navigation system 96 that one's automobile on whichthe vehicle lighting fixture 100 is installed is running at moderatespeed (city driving), the “standard light distribution” can beautomatically selected and the “standard light distribution process” canbe performed (step S22).

Furthermore, for example, if it is determined on the basis of thenavigation information from the navigation system 96 that one'sautomobile on which the vehicle lighting fixture 100 is installed isrunning along a rough road, the “wide-zone important light distribution”can be automatically selected and the “wide-zone important lightdistribution process” can be performed (step S26).

Other than the above determination based on the navigation information,vehicle speed information from the vehicle speed sensor 98 a, windshieldwiper information from the windshield wiper sensor 98 b, ambientluminance information from the ambient luminance sensor 98 c, etc. canbe used to determine the conditions surrounding one's automobile onwhich the vehicle lighting fixture 100 is installed. According to thedetermined conditions, the “hot-zone important light distributionprocess” (step S18), “hot-zone brighter light distribution process”(step S20), “standard light distribution process” (step S22), “wide-zonebrighter light distribution process” (step S24), and “wide-zoneimportant light distribution process” (step S26) may be automaticallyexecuted.

The processes in steps S12 to S28 can be repeatedly performed until theheadlamp switch 90 is tuned off (step S30, SW=OFF). Then, when theheadlamp switch 90 is turned off, the oscillation of the respectivelaser light sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductorlasers LD_(LL1), LD_(LL2), and LD_(LL3)) is stopped (step S32) tocomplete each of the processes.

Next, the first to third condenser lenses 78 _(Wide), 78 _(Mid), and 78_(Hot) will be described with reference to a specific example.

FIG. 34A illustrates a specific example (aspheric lens) of the first tothird condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) that canconverge the laser light rays dispersed by the respective diffractionoptical elements 80 _(DO1-1) to 80 _(DO1-3), 80 _(DO2-1) to 80 _(DO2-3),and 80 _(DO3-1) to 80 _(DO3-3) and cause the same to be incident on therespective optical fibers 36 _(Wide), 36 _(Mid), and 36 _(Hot) withoutloss. The incident surface and output surface of each of the first tothird condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) asillustrated in FIG. 34A can be an aspheric surface represented by thefollowing formula.

${{Sag}(x)} = \frac{\frac{x^{2}}{r}}{1 + \sqrt{1 - {\left( {1 + c} \right)({xr})^{2}}}}$

Specifically, the first to third condenser lenses 78 _(Wide), 78 _(Mid),and 78 _(Hot) can have a curved cross section of an aspheric lensdefined by a sagging value at a position which is separated away fromthe lens center line by a distance x to the outer periphery of the lens.

The sagging value Sag(x) represents a distance from the lens top at aposition which is separated away from the center line of the opticalaxis of the lens by a distance x as illustrated in FIG. 34A.Furthermore, r is a radius of curvature when c=0, and c is an asphericsurface coefficient.

FIG. 34B is a schematic diagram illustrating the state in which, whenparallel light rays to the optical axis of the first to third condenserlenses 78 _(Wide), 78 _(Mid), and 78 _(Hot) are incident on the first tothird condenser lenses 78 _(Wide), 78 _(Mid), and 78 _(Hot), the lightrays are condensed and incident on the light incident surface of anoptical fiber. FIG. 34C is a schematic diagram illustrating the state inwhich, when light rays tilted by 10 degrees with respect to the opticalaxis are incident on the first to third condenser lenses 78 _(Wide), 78_(Mid), and 78 _(Hot), the light rays are condensed and incident on thelight incident surface of the optical fiber.

Note that each of the optical fibers 36 _(Wide), 36 _(Mid), and 36_(Hot) in FIGS. 34A to 34C have a diameter of 1 mm and Na>0.82.

As described above, according to the present exemplary embodiment, thevehicle lighting fixture can be configured to form predetermined lightdistribution patterns (for example, a high-beam (driving) lightdistribution pattern P_(Hi) or a low-beam (passing) light distributionpattern P_(Lo)) formed by superimposing a plurality of partial lightdistribution patterns P_(Hi) _(_) _(Wide), P_(Hi) _(_) _(Mid), andP_(Hi) _(_) _(Hot) (or partial light distribution patterns P_(Lo) _(_)_(Wide), P_(Lo) _(_) _(Mid), and P_(Lo) _(_) _(Hot)), and in particular,can change a light intensity of at least one partial light distributionpattern (for example, hot-zone partial light distribution pattern P_(Hi)_(_) _(Hot)) out of the plurality of partial light distributionpatterns. As a result, the high-beam light distribution pattern P_(Hi)(or the low-beam light distribution pattern P_(Lo)) can be madeappropriate for the conditions surrounding the vehicle body, or therunning conditions.

This can be achieved by the light intensity changing unit (see FIG. 32)configured to change a light intensity of at least one partial lightdistribution pattern (for example, hot-zone partial light distributionpatterns P_(Hi) _(_) _(Hot)) out of the partial light distributionpatterns P_(Hi) _(_) _(Wide), P_(Hi) _(_) _(Mid), and P_(Hi) _(_) _(Hot)(or partial light distribution patterns P_(Lo) _(_) _(Wide), P_(Lo) _(_)_(Mid), and P_(Lo) _(_) _(Hot)).

Specifically, this can be achieved by switching over the diffractiveoptical element to be disposed in the optical path of laser light fromeach of the laser light source 74 _(LL1), 74 _(LL2), and 74 _(LL3) foreach laser light source so that an output of laser light exiting throughthe output end face of at least one optical fiber (for example, thehot-zone optical fibers 36 _(Hot)) out of the optical fibers 36 _(Wide),36 _(Mid), and 36 _(Hot) increases, whereby the laser light with therelatively increased output can form a particular partial lightdistribution pattern (for example, hot-zone partial light distributionpattern P_(Hi) _(_) _(Hot)).

Furthermore, with the above-described vehicle lighting fixture 100,without changing the outputs of laser light from the respective laserlight sources 74 _(LL1), 74 _(LL2), and 74 _(LL3) (semiconductor lasersLD_(LL1), LD_(LL2), and LD_(LL3)), i.e., with the outputs of laser lightfrom the respective laser light sources 74 _(LL1), 74 _(LL2), and 74_(LL3) (semiconductor lasers LD_(LL1), LD_(LL2), and LD_(LL3)) beingmaintained, at least one partial light distribution pattern (forexample, hot-zone partial light distribution pattern P_(Hi) _(_) _(Hot))can be changed.

This is because the diffractive optical element to be disposed in theoptical path of laser light of each of the laser light sources 74_(LL1), 74 _(LL2), and 74 _(LL3) is switched over to another for eachlaser light source, thereby changing the light intensity of theparticular partial light distribution pattern (for example, hot-zonepartial light distribution pattern P_(Hi) _(_) _(Hot)).

Furthermore, the above-described vehicle lighting fixture 100 can beconfigured to manually or automatically form the high-beam lightdistribution pattern P_(Hi) (or a low-beam light distribution patternP_(Lo)) that can be made appropriate for the conditions surrounding thevehicle body, or the running conditions.

A description will now be given of a modified example of the vehiclelighting fixture 100 according to the presently disclosed subject matteras a vehicle lighting fixture 100A.

FIG. 35 is a schematic diagram illustrating the configuration of thevehicle lighting fixture 100A as a modified example.

The vehicle lighting fixture 100A of this modified example can beconfigured in the same manner as in the vehicle lighting fixture 100,except that the lighting unit 40 constituting the vehicle lightingfixture 100 of the above-described exemplary embodiment is replaced bylighting units 40 _(Wide), 40 _(Mid), and 40 _(Hot).

Examples of the lighting units 40 _(Wide), 40 _(Mid), and 40 _(Hot) inthis modified example may include a projector-type lighting unit, areflector-type lighting unit, a direct projection-type lighting unit,and other types of lighting units.

The output ends of the respective optical fibers 36 _(Wide), 36 _(Mid),and 36 _(Hot) can be attached to the lighting units 40 _(Wide), 40_(Mid), and 40 _(Hot), respectively.

In this configuration, the wide-zone lighting unit 40 _(Wide) can formthe wide-zone partial light distribution pattern P_(Hi) _(_) _(Wide) asillustrated in FIG. 3A using laser light rays propagating through thewide-zone optical fibers 36 _(Wide). Specifically, the wide-zonelighting unit 40 _(Wide) can include a phosphor configured to be excitedby the laser light rays propagating through the wide-zone optical fibers36 _(Wide), and an optical system (lens and/or reflecting mirror)configured to project light from the phosphor forward to form thewide-zone partial light distribution pattern P_(Hi) _(_) _(Wide) asillustrated in FIG. 3A.

Similarly, the middle-zone lighting unit 40 _(Mid) can form themiddle-zone partial light distribution pattern P_(Hi) _(_) _(Wide) asillustrated in FIG. 3A using laser light rays propagating through themiddle-zone optical fibers 36 _(Mid). Specifically, the middle-zonelighting unit 40 _(Mid) can include a phosphor configured to be excitedby the laser light rays propagating through the middle-zone opticalfibers 36 _(Mid), and an optical system (lens and/or reflecting mirror)configured to project light from the phosphor forward to form themiddle-zone partial light distribution pattern P_(Hi) _(_) _(Mid) asillustrated in FIG. 3A.

Similarly, the hot-zone lighting unit 40 _(Hot), can form the hot-zonepartial light distribution pattern P_(Hi) _(_) _(Hot) as illustrated inFIG. 3A using laser light rays propagating through the hot-zone opticalfibers 36 _(Hot). Specifically, the hot-zone lighting unit 40 _(Hot) caninclude a phosphor configured to be excited by the laser light rayspropagating through the hot-zone optical fibers 36 _(Hot), and anoptical system (lens and/or reflecting mirror) configured to projectlight from the phosphor forward to form the hot-zone partial lightdistribution pattern P_(Hi) _(_) _(Hot) as illustrated in FIG. 3A.

Also this modified example can execute the same processes as illustratedin FIG. 32 to exert the same advantageous effects as those exerted bythe above-described exemplary embodiment.

The respective numerical values used in the above-described exemplaryembodiments and the modified example are illustrative and explanatory,and can appropriately take other numerical values so long as theabove-described exemplary embodiments and the modified example can beconfigured as described in the claims.

Further, it will be apparent to those skilled in the art that variousmodifications and variations can be made in the presently disclosedsubject matter without departing from the spirit or scope of thepresently disclosed subject matter. Thus, it is intended that thepresently disclosed subject matter cover the modifications andvariations of the presently disclosed subject matter provided they comewithin the scope of the appended claims and their equivalents. Allrelated art references described above are hereby incorporated in theirentirety by reference.

What is claimed is:
 1. A vehicle lighting fixture configured to form apredetermined light distribution pattern by superimposing N partiallight distribution patterns wherein N is a natural number of 2 or more,the vehicle lighting fixture comprising: N optical fibers providedcorresponding to the respective N partial light distribution patterns; Nlaser light sources provided corresponding to the respective N opticalfibers; N sets of at least one diffractive optical element providedcorresponding to the respective N laser light sources; N actuatorsprovided corresponding to the respective N laser light sources and eachconfigured to dispose any one diffractive optical element of acorresponding one set of the N sets of the at least one diffractiveoptical element corresponding to one of the N laser light sources in anoptical path of laser light from a corresponding one of the N laserlight sources; and a lighting unit configured to form the predeterminedlight distribution pattern with the laser light propagating through theN optical fibers, wherein when each diffractive optical element of anyone set of the N sets of at least one diffractive optical element isdisposed in the optical path of laser light from the corresponding oneof the N laser light sources, the one of the plurality of diffractiveoptical elements is configured to deflect the laser light from thecorresponding one of the N laser light sources toward respectiveincident end faces of the N optical fibers at respective disperse ratiosby diffracting the laser light from the corresponding one of the N laserlight sources, and each of the N actuators is configured to switch overeach diffractive optical element of a corresponding one set of the Nsets of the at least one diffractive optical element to be disposed inthe optical path of laser light of the corresponding one of the N laserlight sources for each laser light source so that an output of laserlight exiting through an output end face of each optical fiber out ofthe N optical fibers becomes a predetermined output ratio, to therebychange the light intensity of at least one partial light distributionpattern out of the N partial light distribution patterns.
 2. The vehiclelighting fixture according to claim 1, wherein the vehicle lightingfixture is configured to form a plurality of predestined lightdistribution patterns and comprises a sensor installed in a vehiclebody, and when one light distribution pattern among the plurality ofpredetermined light distribution patterns is selected on the basis of amanual operation or an automatic operation based on information from thesensor installed in the vehicle body, the actuator switches over thediffractive optical element to be disposed in the optical path of thelaser light of the laser light source for each laser light source so asto form the one light distribution pattern selected manually orautomatically.
 3. The vehicle lighting fixture according to claim 2,wherein the diffractive optical elements are each any one of aholographic optical element and a blazed diffractive optical element. 4.The vehicle lighting fixture according to claim 1, wherein thediffractive optical elements are each any one of a holographic opticalelement and a blazed diffractive optical element.
 5. The vehiclelighting fixture according to claim 1, wherein the vehicle lightingfixture has an optical axis extending in a front-to-rear direction of avehicle to which the vehicle lighting fixture is to be mounted, and thelighting unit includes a projection lens, a member of which an image isto be projected, and an optical deflector that are disposed in theoptical axis in this order.
 6. The vehicle lighting fixture according toclaim 5, wherein the optical deflector is provided to each of the Noptical fibers at the output end face thereof, and the member of whichan image is to be projected is a wavelength conversion member includinga scanning region by the optical deflector.
 7. The vehicle lightingfixture according to claim 6, wherein the projection lens is aprojection lens assembly composed of a plurality of lenses.
 8. Thevehicle lighting fixture according to claim 6, wherein the opticaldeflector is operated by at least one of a piezoelectric system, anelectrostatic system, and an electromagnetic system.
 9. The vehiclelighting fixture according to claim 6, wherein the number of the Noptical fibers is three, the optical deflector includes three opticaldeflectors, and the member of which an image is to be projected has asurface facing to the projection lens, the surface including a scanningregion by the three optical deflectors.
 10. The vehicle lighting fixtureaccording to claim 5, wherein the projection lens is a projection lensassembly composed of a plurality of lenses.
 11. The vehicle lightingfixture according to claim 5, wherein the number of the N optical fibersis three, the optical deflector includes three optical deflectors, andthe member of which an image is to be projected has a surface facing tothe projection lens, the surface including a scanning region by thethree optical deflectors.
 12. A vehicle lighting fixture configured toform a predetermined light distribution pattern by superimposing Npartial light distribution patterns wherein N is a natural number of 2or more, the vehicle lighting fixture having an optical axis extendingin a front-to-rear direction of a vehicle to which the vehicle lightingfixture is to be mounted, the vehicle lighting fixture comprising: alight intensity changing unit configured to change a light intensity ofat least one partial light distribution pattern out of the N partiallight distribution patterns, a lighting unit including a projectionlens, a member of which an image is to be projected, and an opticaldeflector that are disposed in the optical axis in this order, theoptical deflector is provided corresponding to the light intensitychanging unit, the member of which an image is to be projected is awavelength conversion member including a scanning region by the opticaldeflector with the light from the light intensity changing unit, and theprojection lens is a projection lens assembly composed of a plurality oflenses.
 13. The vehicle lighting fixture according to claim 12, furthercomprising three optical fibers each having an output end face, theoptical fiber receiving the light from the light intensity changingunit, the optical deflector includes three optical deflectorscorresponding to the three output end faces of the optical fibers, andthe wavelength conversion member has a surface facing to the projectionlens, the surface including a scanning region by the three opticaldeflectors.
 14. The vehicle lighting fixture according to claim 13,wherein the optical deflector is operated by at least one of apiezoelectric system, an electrostatic system, and an electromagneticsystem.